Back Material Research Articles

Microfluidic Precision Manufacture of High Performance Liquid Chromatographic Microspheres

A key bottleneck in developing chromatographic material is the chemically entangled control of morphology, pore structure, and material chemistry, which holds back precision material manufacture in order to pursue advanced separation performance. In this work, a precision manufacture strategy based on droplet microfluidics was developed, for production of highly efficient chromatographic microspheres with independent control over particle morphology, pore structure and material chemistry. The droplet‐synthesized microspheres display extremely narrow particle size distribution (CV<3%), enabling a 100% production yield due to complete elimination of sieving steps. More importantly, the size of the droplet‐synthesized microspheres is freely adjustable without the need for re‐optimizing chemical recipes or reaction conditions. The resulting materials exhibit excellent separation efficiencies, achieving a reduced plate height of hmin​=1.67. This precision manufacture strategy also allows for flexible pore design and continuous pore size adjustment across three orders of magnitudes, providing a novel vehicle for resolution fine‐tuning targeting protein separation. Besides traditional silica, organic‐inorganic hybrid silica, zirconia, and titania microspheres can also be precisely synthesized on the same platform, supporting various separation applications and operating conditions. Powered by precision manufacture, super‐throughput production, and versatile chemistry, the high‐performance droplet‐synthesized separation material will pave the way towards green and precision chromatographic industry.

Microfluidic Precision Manufacture of High Performance Liquid Chromatographic Microspheres.

A key bottleneck in developing chromatographic material is the chemically entangled control of morphology, pore structure, and material chemistry, which holds back precision material manufacture in order to pursue advanced separation performance. In this work, a precision manufacture strategy based on droplet microfluidics was developed,for production of highly efficient chromatographic microspheres with independent controloverparticle morphology, pore structureand material chemistry.The droplet-synthesized microspheres display extremely narrow particle size distribution (CV<3%), enabling a 100% production yield due to complete elimination of sieving steps. More importantly, the size of the droplet-synthesized microspheres is freely adjustable without the need for re-optimizing chemical recipes or reaction conditions. The resulting materials exhibit excellent separation efficiencies, achieving a reduced plate height of hmin​=1.67. This precision manufacture strategy also allows for flexible pore design and continuous pore size adjustment across three orders of magnitudes, providing a novel vehicle for resolution fine-tuning targeting protein separation. Besides traditional silica, organic-inorganic hybrid silica, zirconia, and titania microspheres can also be precisely synthesized on the same platform, supporting various separation applications and operating conditions. Powered by precision manufacture, super-throughput production, and versatile chemistry, the high-performance droplet-synthesized separation material will pave the way towards green and precision chromatographic industry.

Components and defect density optimization of FAxMA1-xPbI3 based on simulation for high performance perovskite solar cells

Choosing FA+/MA+ mixed-ion perovskite material as the active layer of the perovskite solar cells hold out the prospect of high efficiency and high stability. In this paper, the FA+/MA + ratio is modified to optimize the performance of FAxMA1-xPbI3-based perovskite solar cells utilizing SCAPS-1D. The results indicate that the PCE of the devices reached a minimum of 21 % when x is greater than or equal to 0.6 in FAxMA1-xPbI3(FTO/NiOx/FAxMA1-xPbI3/C60/BCP/Al). When x = 0.6, the impact of the bottom interface defects on the solar cell performance is dominant and the thickness of the active layer should be controlled within a range of 0.4 μm–0.8 μm, while the defect density of the layer is expected to be between 1013 1/cm3 and 1014 1/cm3. By optimizing the perovskite layer thickness, defect density and changing the type of back electrode material, the efficiency is reaching 25.74 % based on the device(FTO/NiOx/FA6MA4PbI3/C60/BCP/Au). This study provides theoretical guidance for experimental research on interface modification, defect passivation and manufacturing of high-efficiency FAxMA1-xPbI3-based perovskite solar cells.

Bifacial Wide‐Gap (Ag,Cu)(In,Ga)Se2 Solar Cell with 13.6% Efficiency Using In2O3:W as a Back Contact Material

This study evaluates In2O3:W as a transparent back contact material in wide‐gap (bandgap range = 1.44–1.52 eV) (Ag,Cu)(In,Ga)Se2 (ACIGS) solar cells for potential application as a top cell in a tandem device. High silver concentrations and close‐stoichiometric absorber compositions result in a complete depletion of free charge carriers, allowing for decent electron collection, despite the low diffusion length. Remarkable efficiencies of 13.6% and 7.5% are reached using 1 μm‐ and 400 nm‐thick absorbers, respectively. At rear illumination (i.e., superstrate backwall), the best cell shows an efficiency of 8.7%. For each of the four analyzed samples, the short‐circuit current at rear illumination reaches at least 60% of the value at front illumination. Losses arise from recombination at the back contact and a too low drift/diffusion length. The parasitic absorption by the transparent electrodes for photon energies close to the bandgap of a potential Si bottom cell (1.1 eV) is close to 15%. Strategies to reduce this value and to further increase the efficiency are discussed.

2D Dion Jacobson/3D perovskite heterojunction solar cells without hole transport layer: Further optimize the performance by SCAPS-1D

The global energy demand is steadily increasing, prompting a widespread focus on renewable energy sources such as solar, wind, hydro, and biomass. Perovskite solar cells (PSCs) have gained considerable attention due to their remarkably high power conversion efficiency (PCE). The Dion-Jacobson (DJ) type two-dimensional layered perovskite material, lacking interlayer van der Waals interaction, enhances device stability significantly. Simultaneously, the heterojunction structure formed by MAPbI3 improves power conversion efficiency (PCE) while maintaining high stability. This study employs 2D Dion Jacobson/3D perovskite heterojunction solar cells for further optimization through simulation analysis using SCAPS-1D (Solar Cells capacitance simulator). The intrinsic impact of heterojunction perovskite solar cells is identified, and appropriate physical parameters are adjusted to approximate experimental results. Optimization variables include absorption layer thickness, absorption layer band gap, interface defect layer thickness, back contact material, and electron transport layer material, all influencing device performance differently. Determining the ideal absorption layer thickness based on absorption characteristics, a hole-free transport layer structure is adopted in this work to reduce production costs and process complexity. To enhance the responsiveness of DJ type two-dimensional layered perovskite materials to various light wavelengths and improve PCE, the simulation employs 3D graphics to optimize variables such as the absorption layer's band gap. The highest PCE achieved is 27.42 %. Additionally, the study explores device performance in a low-temperature operating environment (265 ∼ 325 K). At 265 K, the PCE and fill factor (FF) are 29.37 % and 85.45 %, respectively, indicating that 2D Dion Jacobson/3D perovskite heterojunction solar cells exhibit structural stability and high efficiency at low temperatures compared to other PSCs. These findings suggest promising practical applications in the fields of photovoltaics and optoelectronics.

Dynamic response optimization of the multistage sandwich structures imperiled to explosive loading

Explosive attacks are increasing day by day in the present era, and the design optimization of protective structures without increasing their weight is mainly a critical task for vehicles. Assessment of the dynamic response of the structures under explosive loading through experimentation is costly, with many restrictions, and highly harmful for both people and the environment. Hence, the present study deals with an explicit numerical investigation of the protective sandwich structures’ blast performance. The influence of the number of stages of honeycomb on the sandwich structures’ blast mitigation capacity was evaluated with the effective utilization of face sheets’ material as their intermediate sheets while maintaining the total volumes as well as masses of the structure's constant. The explosive loads of 1 to 3 kg of trinitrotoluene were used for the stand-off distance of 100 mm. The rate-dependent Johnson-Cook plasticity model was implemented on the designed sandwich models to discover their damage behaviors. The sandwiches’ face deflection, energy absorption, kinetic energy variation, and crushing behaviors were considered to characterize their blast mitigation capacity. The obtained results showed that increasing the number of stages of core in the sandwich structure by using a fraction of the back face sheet materials for intermediate sheets significantly improved their blast performance without increasing their volume occupancies and masses. For the two-stage and three-stage sandwich designs, 50% and 20%, respectively, utilization of their back face material for their intermediate sheet was found to be optimal.

EDUKASI LATIHAN UNTUK NYERI PUNGGUNG BAWAH PADA LANSIA DI RW 17 POSLANSIA MOJOSONGO SOLO

Reduced functional ability followed by decreased physical activity has a relationship with age and gender. men and women are at the same risk, ranging from reduced muscle strength to endurance. One disorder that is a common health problem in the world and affects almost the entire elderly population is low back pain. Low back pain is pain felt in the lower back area, not a disease or diagnosis for a disease but is a term for pain felt in the affected body area with various variations in the duration of pain. The purpose of this counseling activity is to provide knowledge about low back pain and exercise education to reduce pain intensity. The activity method used is counseling using leaflets with low back pain material and exercise education. The main targets were members and cadres of the elderly posyandu in RW 17 Mojosongo Solo. The result of this counseling is an increase in public understanding and knowledge about low back pain and exercises to reduce this pain. This proves that the counseling method using leaflets is quite effective. It can be seen from the results of the pre-test and post-test participants who showed an average increase of 45%.

How Well Did ChatGPT Perform in Answering Questions on Different Topics in Gross Anatomy?

The burgeoning interest in leveraging ChatGPT within the medical field underscores the necessity for a comprehensive understanding of its capabilities and limitations, particularly in the context of medical assessments and examinations. The model possesses a unique aptitude for addressing queries related to medical student exams, thereby serving as an invaluable resource for academic support. Its advanced natural language processing capabilities empower it to comprehend the intricacies of medical terminology, enabling it to provide nuanced and contextually relevant responses. This study aimed to quantitatively evaluate ChatGPT performance in answering Multiple Choice Questions (MCQs) related to the different topics in Gross Anatomy course for medical students. The research conducted for this study was focused on a comprehensive examination of ChatGPT (GPT-3.5) capabilities in answering 325 MCQs designed in USMLE style, arranged in 7 different sets related to specific topics. These questions were selected from Gross Anatomy course exam database for medical students and reviewed by three independent experts. The results of 5 successive attempts to answer each set of questions by Chat-GPT were evaluated based on accuracy, relevance, and comprehensiveness. The ChatGPT provided accurate answers to 44.1% ± 8.2% of questions. Accordingly, to our data, ChatGPT is answering much better on MCQs from Back material (58.4%), following Head and Neck (48.8%) and Pelvis (45.6%), and performing not so well in questions of Thorax (37.6%) and Upper limb (36.4%). ChatGPT is struggling in answering questions about blood supply and innervation of the specific organs. ChatGPT stands out as a promising and interactive educational tool, particularly for students engaged in the study of anatomy. Its distinctive ability to not only provide informative responses but also engage students in a conversational manner is highly commendable. This quality has the potential to enhance student engagement and foster curiosity, creating a dynamic learning experience. However, it’s crucial to acknowledge that ChatGPT’s current level of comprehension and interpretative abilities may not meet the demanding standards required for practical applications in the medical education domain. Its performance in challenging examinations like medical college exams and health licensing exams might need to catch up to expectations.

Eco-efficient removal of polymer back sheet fraction and material separation from solar cell waste

This study explores an innovative solution for solar cell waste recycling, addressing current methods' limitations, which often neglect the polymer fraction, and leading to environmental risks. Instead of solely using the traditional thermal treatment, which can release toxic gases from polymer back sheets, this study proposes an alternative approach. The proposed method includes a selective mechanical peeling process supplemented by thermal treatment as the first step to separate the multilayer components of silicon-based PV panels. The experiment used a two-step peeling process: initially isolating the back sheet, then removing non-glass layers from the glass. Subsequent thermal treatments were tested to disintegrate the remaining polymers and separate materials optimally. The proposed method's effectiveness and environmental implications are compared to traditional methods using Raman spectroscopy, FTIR, XRD, XRF, and gas chromatography. Findings indicate the proposed method reduces energy consumption and pollutant emissions while increasing the purity of recovered materials.

Comparative study of compound parabolic concentrator - photovoltaic thermal – thermoelectric generator (CPC-PVT-TEG) collector integrated with vapour absorption refrigeration (VAR) system

ABSTRACT In this communication, a hybrid CPC-PVT-TEG collector integrated with the VAR system has been analyzed, taking into consideration 3 different types of PV modules based on their back cover material, namely Tedlar (Case 1), Aluminium (Case 2) and semi-transparent (glass to glass) (Case 3). The simulation of the whole system, including the hybrid collector and VARS, has been done for a clear day in May in New Delhi using MATLAB 2021b. A comparative study has been conducted between the three cases and based on the results obtained from the analysis, the overall exergy (EEX), overall exergy efficiency (ηEX), daily electrical energy and overall exergy attained their highest values for Case 2 [Aluminum based] with their values being 289.33 Wh, 28.92%, 2.37 kWh and 2.55 kWh, respectively. The coefficient of performance (COP), which is a measure of the refrigeration effect of the VAR system, attained its highest value for Case 3 [glass to glass based] at 1.28 and lowest value for Case 1 [Tedlar based] at 0.28. Also, from a purely overall exergy aspect, the aluminum-based hybrid CPC-PVT-TEG collector integrated with the VAR system (Case 2) is found to be the most suitable with exergy and exergy efficiency values and from the refrigeration as well as from a thermal exergy aspect, the semitransparent-based or glass to glass-based hybrid CPC-PVT-TEG collector integrated with a VAR system (Case 3) is found to be the most suitable.

Prediction of bending strength of glass fiber reinforced methacrylate-based pipeline UV-CIPP rehabilitation materials based on machine learning

Ultraviolet cured-in-place-pipe (UV-CIPP) materials are commonly used in trenchless pipeline rehabilitation. Their bending strength is a crucial indicator to evaluate the curing quality. Studies show that this indicator is affected by multiple factors, including the curing time, UV lamp curing power, curing distance, and material thickness. Laboratory experiments have limitations in analyzing the effect of multiple factors on the bending strength of UV-CIPP materials and quantitatively predicting the optimum curing parameters. Aiming at resolving these shortcomings, resolve machine learning techniques were applied to predict the bending strength. In this regard, the surface curing reaction temperature monitoring data and three-point bending data of 30 groups of UV-CIPP material under the influence of different curing parameters were used as a dataset to predict the bending strength of UV-CIPP material. The results show that the influence degree of each factor on the bending strength of the UV-CIPP material, from high to low, is as follows: UV lamp power (−0.439), the temperature at the illuminated side (−0.392), curing time (−0.323), the temperature at the back side (−0.233), curing distance (0.143) and material thickness (−0.140). The best penalty parameter c (44.435) and width g (0.072) of the kernel function in the support vector machine (SVM) model were obtained using the genetic algorithm (GA) optimization, and the results were compared with the grey wolf optimizer (GWO) and particle swarm optimization (PSO). The performed analyses revealed that the developed GA-SVM model exhibits the best prediction results compared to other machine learning algorithms. The optimum bending strength of the UV-CIPP material used in this test is 294.77 MPa, which corresponds to the curing time, UV lamp power, curing distance, material thickness, light side temperature, and back side temperature of 7.59 min, 157.33 mW/cm2, 189.99 mm, 4.38 mm, 79.49 °C, and 76.59 °C, respectively.

Effect of organic charge transport layers on unleaded KSnI3 based perovskite solar cell

The implementation and commercialization of perovskite solar cells (PSCs) is hindered due to lead, which has a toxic nature. The inorganic charge transport layers (CTLs) require complex deposition techniques, which are not very cost friendly and the reported efficiencies of PSC with organic CTLs are higher than those with inorganic CTLs. In the present work, a theoretical study of the effect of organic CTLs on a KSnI3 based PSC is carried out using SCAPS software. The defect concentration of the layers and the interfaces, doping density and thickness of the layers, and the shunt and series resistance of the device is optimized. Carbon is suggested as an affordable alternative to state-of-the-art back contact material (BCM), gold. The stability of this device with temperature is also established. The optimized solar cell showed an excellent fill factor (FF) of 80.80% with a power conversion efficiency (PCE) of 10.83% and a very good quantum efficiency (QE) in the visible region.

75‐3: Investigation of Influence and Improvement of Dry Etch on Glass Strength

None film surface of TFT glass will be damaged varying degrees due to physical contact with array equipment, which will seriously reduce the strength of none film surface. In this paper, we clarified the physical damage caused by the dry etch equipment on none film surface of TFT and its impact on the strength reduction through multiple verifications in array process. It is proved that strength reduction is mainly related to the back electrode material of dry etch. By changing the back electrode material from M to N(code name), the strength of the acrylic ball drop increased by more than 500%, and the strength of the cell ROR increased by 57%. This research has greatly improved the strength of none film surface of LCD, which is great significant to product performance improvement and new product certification.

Simulation of Carbon-Based Perovskite Solar Cell Using PBS-TBAI as a Hole Transport Layer (HTL)

Perovskite material is a propitious candidate for high-efficiency and cost-efficient solar cells. Inorganic and organic perovskite materials show outstanding electrical and optical characteristics. As an absorber layer, it attracts the researchers due to its tunable bandgap, higher carrier mobility, and higher absorption coefficient. In this article, CH3NH3PbI3-based solar cell is proposed with architecture FTO/TiO2/CH3NH3PbI3/PbS-TBAI/Carbon. The present study shows that carbon as back contact is cost-efficient material and shows stable performance. Thickness variation of absorber layer (CH3NH3PbI3) and variation in temperature has been done for device optimization and its J–V characteristics and quantum efficiency are studied. Optimum thickness of absorber layer for donor density of 1.0×1013 cm−3 and acceptor density of 1.0×1012 cm−3 is estimated to be 1 μm. This n-i-p planar architecture stands out with a fill factor of 36.75% and a power conversion efficiency of 7.59% with Jsc and Voc value of 24.55 mA/cm2 and 0.84 V respectively. Without resistance the device architecture bears Voc 0.8 V, Jsc 25.73 mA/cm2, FF 80.33% and PCE of 16.24%. The simulation has been performed using SCAPS-1D at an optimized temperature of 300 K and at an AM 1.5 G illumination. The present study is useful in selecting material parameters and fabricating efficient and low-cost perovskite solar cells.

Design and Performance Exploration of a Lead‐Free All‐Inorganic Hydrogenated Cs2AgBiBr6‐Based Double Perovskite Solar Cell: A Numerical Modeling Study

Lead‐free double perovskite Cs2AgBiBr6 has attracted wide attention owing to its nontoxic and stable properties. Recently, hydrogenated Cs2AgBiBr6 (HCABB) films have been shown to possess superior optoelectronic properties than pristine Cs2AgBiBr6, and the double perovskite solar cell (DPSC) based on the films broke the efficiency record of DPSCs as soon as it was proposed. However, its poor energy band alignment and thin absorber layer thickness prevent HCABB from realizing its full photovoltaic potential. In this article, we design a lead‐free all‐inorganic HCABB‐based DPSC for application purposes. To explore its photovoltaic potential, we numerically optimize the transport layer materials, the thickness and bulk defect density of the absorber layer, the interface defect densities, the back contact material, and the parasitic series and shunt resistances step by step for the HCABB‐based DPSC. We predict the HCABB‐based DPSC with the structure of FTO/Nb2O5/HCABB/CuI/Cu can achieve an open‐circuit voltage of 1.139 V, short‐circuit current density of 22.40 mA cm−2, fill factor of 83.35%, and power conversion efficiency of 21.28%. Overall, our work explores the photovoltaic potential of HCABB and provides guidance for fabricating more efficient HCABB‐based DPSCs.

Development of front and back rolling mobile learning media for class x students of SMAN 1 Pamekasan

Many students do not understand the gymnastic movements being taught and become bored with the movement, as well as the learning method. This study aims to produce a learning media device in physical education, sports and health in the form of mobile learning floor exercise with front roll and back roll material for student’s class X of SMAN 1 Pamekasan so that it can be a teaching material. In this study, the Research and Development (R&amp;D) from Lee and Owens was. So that only 5 steps are in accordance with the conditions in the field. (1) needs analysis, (2) product design, (3) development related to the material to be developed (4) application/implementation, (5) product evaluation by experts and product trials. Results of product development data obtained the first result (91.3%) with 32 students and the second group (87.4%) with 115 students. From the results of these data, it can be concluded that the criteria for learning media products for floor exercise materials based on mobile learning have very valid criteria and are suitable for use in learning activities in schools.

Investigation of back barrier material effects on the scalability of Fe-doped recess-gated AlN/GaN HEMTs for next generation RF power electronics

GaN HEMTs (high-electron-mobility transistors) on SiC (silicon carbide) wafer with back barrier structures have gained much attention owing to the improved sheet charge density through enhanced carrier confinement, which can accomplish further improvement of RF performance. In this simulation work, the influence of different back barrier materials on RF & DC performance of Fe-doped recess gated AlN/GaN HEMT is explored. This paper also investigates the back barrier thickness effects on carrier confinement of each structure; the results show that better confinement of carriers in the GaN channel is accompanied by an optimized thickness for each back barrier material besides which, the performance is comparatively degraded. As back-barrier based structures have the capability to reduce SCEs by enhancing the carrier confinement, the investigation is done to analyse the impact of gate length scalability on the DC & RF characteristics of the proposed device. Lg = 60 nm Fe-doped recess-gated AlN/GaN HEMT with an optimized AlGaN back barrier thickness of 60 nm provided a peak drain current of 4.63 A/mm, the highest transconductance of 2333 mS/mm, and the highest cut-off frequency of 316.6 GHz, and this outstanding DC/RF performance is due to strong carrier confinement and reduced leakage current. This outstanding performance makes them a potential choice for future RF power electronics and MMIC design.

Development of correlation between temperature, liquid life span, molten pool, and porosity during Wire Arc Additive Manufacturing: A finite element approach

In recent times additive manufacturing (AM) has emerged as a crucial manufacturing process for custom-made metal workpieces. Wire Arc Additive Manufacturing (WAAM) is a rising technology that can cut back material usage and manufacturing time due to its higher deposition rate. This research aims to develop an efficient 3D thermal model to simulate the WAAM process and correlate the temperature with deposition quality. A moving heat source based on Goldac’s double ellipsoidal model was designed using the DFLUX subroutine. The element birth technique has been used to activate the various layers. The developed model is validated with experimentally observed temperature, and a good correlation is obtained. The effect of power and scan speed on the WAAM process has been studied to develop a relationship between maximum temperature, liquid lifetime, and porosity. An X-ray was done to check the porosity of the additively manufactured specimen. At higher power and lower scan speed, the liquid lifetime was observed to be increased along with the increase in depth of the molten pool leading to the formation of porosity. In other cases, at lower power and higher scan speed, the liquid lifetime was observed to be decreased along with the decrease in depth of the molten pool. The higher scan speeds resulted in higher cooling rates, which caused a lack of fusion between the layers of the product. In this case, a ball-shaped melt deposit was observed due to a lower deposition rate due to lower power. • A thermal model is developed to simulate WAAM and is validated with the experimentally observed temperature. • The element birth technique has been used to activate the various layers during the process. • A correlation between maximum temperature, liquid lifetime, and porosity is established. • Temperature contour and liquid lifespan can predict the formation of porosity during the process.

IMPROVING THE BASIC MOVEMENT OF BACK BOLSTERS USING THE TPACK-BASED PBL MODEL FOR GRADE V STUDENTS OF SD NEGERI SIEM, ACEH BESAR DISTRICT

Physical education, health and sports is a very complete subject because it is able to develop all aspects that exist in students. Elementary school students are students who must be well shaped by all aspects that exist in themselves, namely aspects of skills, social, emotional and personality. However, at SD Negeri Siem, in class V, there is a problem, namely the back roll material. The problem that arises is in the aspect of student skills, students have not been able to do a back roll well. Based on the existing problems, an idea was born as a solution to the problem, namely Improving the Back Rolling Basic Motion Using the TPACK-based PBL model for Class V students of SD Negeri Siem, Aceh Besar District. The formulation of the problem is as follows; Can the TPACK-based PBL model improve the basic back bladder movement for Class V students at SD Negeri Siem, Aceh Besar District? The purpose of this study was to find out that the TPACK-based PBL model could improve the basic movements of the back bladder for fifth graders at SD Negeri Siem, Aceh Besar District. This research uses classroom action research method. The results of this study, namely in Cycle I, it was known that the number of students was 26 people with a total score of 1775, the average value of students was 68.27 with the highest score of 80 and the lowest score of 50. 50%) and 13 people (50%) who did not complete it. And the second cycle is known that the number of students as many as 26 people with a total score of 1985, the average value of students is 76.35 with the highest score of 90 and the lowest score of 50. So it can be seen also that the students who completed are 24 people (92.31% ) and 2 people who did not complete it (7.69%). The conclusion is that the TPACK-Based PBL Model can improve the basic movements of the back bladder for Class V students of SD Negeri Siem, Aceh Besar District.

Evaluation of PbTe and SnTe as ohmic contact layers in CdTe solar cell devices

For solar cells based on CdTe, the choice of a suitable back contact material is limited by CdTe’s deep work function. Here, we explored p-type PbTe and SnTe as ohmic contacts to CdTe. These contact layers were grown on single crystal CdTe substrates by molecular beam epitaxy, and the valence band offset between film and substrate was measured using X-ray photoemission spectroscopy. Polycrystalline device structures were also grown by sublimation to assess performance improvements. Doping was achieved in PbTe by thallium incorporation. Only the highest Tl doped PbTe resulted in a desirable band alignment with the CdTe, forming an electron reflector and no hole barrier. Time-resolved photoluminescence measurements also revealed significant photocarrier lifetime improvements for only the highest doped PbTe. Consequentially, devices incorporating the highest doped PbTe layers showed increased power conversion efficiency, primarily from increased fill factor. Doping of the PbTe was measured via Hall effect with variable magnetic field, which was required due to the formation of an n-type parasitic interface layer. To properly interpret the variable field Hall measurements, we derived an expression for the magnetic field-dependent conductivity tensor of an L-valley semiconductor.