eV Band Gap Research Articles

Nd doped ZrO2 photocatalyst for organic pollutants degradation in wastewater

Wastewater management is the most discussed topic in this current era. To overcome the scarcity of water and wastewater treatment, reusage of water is the convenient way. By removing the organic pollutants, the water can be reused for domestic purposes. Pure and neodymium (Nd) doped ZrO 2 was produced using facile co-precipitation technique. Along with doping, surfactant was also included to enhance the morphology of the prepared samples. The nanoparticles morphology was formed with less agglomeration as investigated by TEM analysis. The photocatalytic action was further examined using annular photoreactor. Both methylene blue (MB) and Rhodamine B (RhB) dyes degradation was examined. Neodymium doped ZrO 2 was incorporated in the dye under visible light for 2 h. The light was irradiated for 20 min and sample solution was collected for every 20 min. The samples were analyzed for UV and degradation was confirmed. The enhancement of catalyst depended on the bandgap of the samples. The absorption peak for Rhodamine B and Methylene Blue dyes at 553 and 664 nm was decreased and confirmed the degradation of dyes. 2% Nd doped ZrO 2 catalyst added MB dye sample showed 90% efficiency and exhibited 77% efficiency on Rhodamine B pollutant. The “k” values of 2% Nd doped ZrO 2 was obtained as 0.0144 min −1 and 0.00944 min −1 for MB and RhB dyes. This candidate will be the potential one for futuristic water remediation process. • 1.23 eV band gap 2% Nd-ZrO 2 explored highly active during photocatalysis. • 2% Nd-ZrO 2 showed 90% efficiency on reducing MB dye. • 2% Nd-ZrO 2 showed 77% efficiency on reducing RhB dye. • The rate constant of 2% Nd-ZrO 2 added MB dye sample was 0.0144 min −1 . • The rate constant of 2% Nd-ZrO 2 added RhB dye sample was 0.00944 min −1 .

The effect of CO2-doped spiro-OMeTAD hole transport layer on FA(1−x)CsxPbI3 perovskite solar cells

Black-phase formamidinium lead iodine with 1.48 eV bandgap is considered to be the most promising material for improving the near-theoretical limit efficiency of perovskite solar cells, but at room temperature, black-phase formamidinium lead iodine easily transforms into the yellow non-perovskite phase formamidinium lead iodine. Here, different ratios of Cs+-incorporated formamidinium lead iodine prepared by one-step processing with the stability and power conversion efficiency of formamidinium lead iodine perovskite solar cells are investigated. FA0.85Cs0.15PbI3 shows the highest power conversion efficiency of 10.63% (Voc = 1.04 V, Jsc = 16.81 mA cm−2, and fill factor = 0.60), and the unencapsulated device maintained 60% of the initial power conversion efficiency after storage in air with 40% humidity for 186 h with an active area of 0.1 cm2, when the ratios of Cs+ reached 15% ( x = 0.15) in formamidinium lead iodine. However, the efficiency of perovskite solar cell–based formamidinium lead iodine is still low. In this work, a simple but an effective strategy was carried out to rapidly and fully oxidize hole transport layer solution by doping CO2 or O2 under ultraviolet light irradiation to increase the conductivity of hole transport layer, thereby improving the power conversion efficiency of solar cells. The results show that FA0.85Cs0.15PbI3 solar cells by CO2-doped hole transport layer for 90 s exhibited the highest power conversion efficiency of 16.11% (VOC = 1.11 V, JSC = 19.73 mA cm−2, and fill factor = 0.74). The improved photovoltaic performance is attributed to CO2-doped spiro-OMeTAD increasing charge carrier density and accelerating charge separation, thereby inducing higher conductivity. CO2 or O2 doped can rapidly and fully oxidize spiro-OMeTAD, and reduce the solar cell fabrication time; it is beneficial to the commercial use of perovskite solar cells.

Vacancy ordered Cs2SnX6 (X = Cl, Br, I) double perovskites as an absorber and antiferromagnetic NiO with GO as a hole transport layer for highly efficient heterojunction solar cell application

This article investigates the vacancy ordered Cs2SnX6 (X = Cl, Br, I) double perovskites (VODP) using jTB-mBJ XC potentials and conclusively noticed that jTB-mBJ’s refined parameters are transferable to VODPs for accurate prediction of material properties. The article presents a comparative analysis of CsMX3 perovskites. Further, a mixed Mott-Hubbard and charge-transfer state for antiferromagnetic NiO is predicted with an agreeable 4.15 eV band gap using TB-mBJ XC potential. VODP Cs2SnI6 as an absorber is integrated with NiO and graphene oxide (GO) as an effective HTM and interlayer, respectively, in an inverted configuration, showing 27.07 % photoconversion efficiency under optimal device parameters. The impact of various materials’ parameters is also investigated to understand the correlation between materials parameters and photovoltaic (PV) performance. Thus, the present study may bring a new dimension to VODP-based photovoltaic materials and devices.

Suppressing Phase Segregation in Wide Bandgap Perovskites for Monolithic Perovskite/Organic Tandem Solar Cells with Reduced Voltage Loss.

Wide bandgap (WBG) perovskites through tuning iodine/bromine ratios are capable of merging with narrow bandgap organic bulk heterojunctions to construct tandem solar cells to overcome the Shockley-Queisser limitation. However, WBG perovskites readily suffer from light-induced halide ion migration, leading to detrimental phase segregation and hence severe open-circuit voltage (VOC ) loss. Here, to solve this issue, lead thiocyanate (Pb(SCN)2 ) and 2-thiopheneethylammonium chloride (TEACl) are synergistically employed to passivate and stabilize WBG perovskites with 1.79eV bandgap. It is demonstrated that the synergetic employment of Pb(SCN)2 and TEACl suppresses light-induced phase segregation, passivates WBG perovskite defects, and reduces non-radiative recombination, hence alleviating VOC loss. As a result, optimized WBG perovskite solar cells (PSCs) are obtained with an impressive VOC of 1.26V and power conversion efficiency (PCE) over 17.0%. Furthermore, the interconnection layer is optimized to minimize the VOC loss and construct two-terminal perovskite/organic tandem solar cells with a narrow bandgap organic blend bulk heterojunction of PM6:Y6 and achieve a champion PCE of 22.29% with a high VOC of 2.072V. In addition, these tandem solar cells maintain 81% of their initial efficiency after 1000h continuous tracking at the maximum power point (MPP) under 100 mW cm-2 white light illumination.

Strategic insight into enhanced photocatalytic remediation of pharmaceutical contaminants using spherical CdO nanoparticles in visible light region

The sustainable control of pharmaceutical micropollutants in water and wastewater environments is a great challenge in the 21st century. To address these issues, unique CdO nanoparticles (NPs) were synthesized using a facile hydrothermal approach and investigated for photocatalytic control of the antibiotic tetracycline, multidrug-resistant bacteria (MDRB), and total coliform in the wastewater effluent. The NPs were characterized using a range of techniques and it exhibited a spherical-like crystal structure with a mean size of 40 nm. The vibrational stretching mode of 1419 cm−1 confirmed the formation of Cd–O (M − O). The synthesis protocol formed smoother surfaces and 1.88 eV band gap energy of CdO NPs, inducing excellent photocatalytic activity under visible LED light (blue and white) irradiation. The optimal catalyst dose and pH were 100 mg/L and 8–9, respectively. Blue light proved more effective than white light, resulting in 28% higher efficiency (93 ± 0.47%) in tetracycline degradation than white light under an identical intensity (20 mW/cm2). White light required a four-fold higher light intensity (80 mW/cm2) than blue light to induce comparable photocatalytic MDRB inactivation. Bacterial cell lysis by the photocatalytic treatment was confirmed by transmission electron microscopy (TEM). The used catalyst was easily recovered by 5 min of centrifugation and re-used without any noticeable change in the photocatalytic decomposition. The trapping experiment revealed that the CdO-based NPs contributed primarily to the generation of •O2− and •OH radicals (Type I), but the •O2− radicals were the dominant reactive oxygen species (ROS) in the photocatalytic process.

Prediction of structural, electronic, and lattice dynamical properties of ABO3 [A = K, Rb, Cs; B = Sn, Sb] perovskite compounds

The structural, elastic, anisotropic, electronic, and lattice dynamical properties of ABO3 (A = K, Rb, Cs; B = Sn, Sb) perovskite compounds were explored using the generalized gradient approximation (GGA) with the ab-initio method based on density functional theory (DFT) implemented in VASP (Vienna Ab-initio Simulation Package). The independent elastic constants of ABO3 perovskite compounds were calculated by using the stress–strain method, and the results show that all compounds are stable as mechanical. The bulk and shear moduli, Young’s modulus, and Poisson’s ratio of the compounds investigated were derived from the calculated elastic constants of the compounds considered. What is more, the ABO3 type perovskite compounds have been determined electronic structure. The study has found that KSnO3 and RbSnO3 have exhibited a semiconductor nature with 0.945 and 0.544 eV bandgaps, respectively. Additionally, the charge transportation of the compounds considered has been assessed using Bader charge analysis. Lattice dynamical properties have been calculated and plotted for compounds considered. The results have been compared to those of other studies, and our findings are consistent with those of other studies.

Ab’initio studies of the structural and electronic properties for single-walled armchair MgONT, SiCNTs and ZnONTs for next generations’ optoelectronics

Due to greater demand to use 1D semiconducting chips to replace semiconductors made from bulk structures We studied the structural and electronic properties of free (7, 0) metallic oxides and non-metallic carbide nanotubes. SWMgONT, SWZnONT and SWSiCNT were chosen as the representative model. All the quantum simulation studies were done within DFT ab’initio implemented in quantum ESPRESSO. Results obtained for structural properties revealed that the most stable bond lengths of MgONT, ZnONT and SiCNT are 1.80 Å, 1.82 Å and 1.42 Å respectively. The results obtained revealed 2.8 eV band gap for SWMgONT, 0.5 eV for SWZnONT and 0.8 eV for SWSiCNT respectively. Furthermore SWMgONT and SWZnONT are regarded as direct band gap semiconductors while SWSiCNT is regarded as an indirect semiconductor with narrow band gap. The narrow band gap of all the three systems obtained demonstrates their potential in the optoelectronic application in the next generations’ sustainability science and technology. Recent studies showed that explorations were conducted on oxide nanotubes such SiO2NT, however to the best of our knowledge, studies of the oxide nanotubes of Mg, Zn and Si have not been reported, hence few literature are available.

Magnetic, Electronic, and Optical Studies of Gd-Doped WO3: A First Principle Study.

Tungsten trioxide (WO3) is mainly studied as an electrochromic material and received attention due to N-type oxide-based semiconductors. The magnetic, structural, and optical behavior of pristine WO3 and gadolinium (Gd)-doped WO3 are being investigated using density functional theory. For exchange-correlation potential energy, generalized gradient approximation (GGA+U) is used in our calculations, where U is the Hubbard potential. The estimated bandgap of pure WO3 is 2.5 eV. After the doping of Gd, some states cross the Fermi level, and WO3 acts as a degenerate semiconductor with a 2 eV bandgap. Spin-polarized calculations show that the system is antiferromagnetic in its ground state. The WO3 material is a semiconductor, as there is a bandgap of 2.5 eV between the valence and conduction bands. The Gd-doped WO3’s band structure shows few states across the Fermi level, which means that the material is metal or semimetal. After the doping of Gd, WO3 becomes the degenerate semiconductor with a bandgap of 2 eV. The energy difference between ferromagnetic (FM) and antiferromagnetic (AFM) configurations is negative, so the Gd-doped WO3 system is AFM. The pure WO3 is nonmagnetic, where the magnetic moment in the system after doping Gd is 9.5599575 μB.

Synthesis and characterization of silver-indium and antimony selenide: role in photocatalytic degradation of dyes

These days, water contamination poses a severe threat to the ecosystem and demands immediate care. This study examined the need to reduce water pollution using clean, renewable energy (solar light irradiations) for the degradation of Congo red by Silver-indium and antimony selenide with chemical composition AgInSbSe3. The sample was fabricated through a hydrothermal technique. The synthesized sample was characterized through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Ultraviolet-Visible spectroscopy. The X-ray diffraction confirms crystalline structure of the synthesized sample. The SEM analysis reveals irregular grains and exhibits a very small inter-particle distance. SEM provides the morphology of the synthesized sample, the grain size of the synthesized sample was 0.58 μm. FTIR results revealed specific absorption bands in the range of 400–4000 cm−1; optical properties are studied through UV-Vis-spectroscopy. The synthesized sample has 1.97 eV bandgap which is suitable for degradation of organic pollutants. The photocatalytic activity of the material is checked by degrading the Congo red dye under direct sunlight irradiation and for the 75 min illumination 77.8% degradation efficiency is attained.

Structural and photodetection studies of hydrothermally grown anatase TiO2 nanomaterial

TiO2 nanomaterial was successfully synthesized via a cost-effective hydrothermal method with a precursor involving titanium tetra isopropoxide (TTIP). The surface morphological and elemental characteristics were confirmed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) respectively. Optical properties of the grown nanomaterial were evaluated using UV–Visible spectroscopy and a 3.45 eV bandgap was estimated from the Tauc plot. From X-ray diffraction (XRD) studies, it was confirmed that prepared nanomaterial possesses crystalline structure with anatase phase. Photodetection of the fabricated photodetector device was carried out under the ambient atmospheric conditions result in responsivity of 15.58 mA/W under 80 μW/cm2 power of incident radiation. The response time and recovery time of the fabricated device find out to be 12.62 sec and 11.89 sec respectively.

Casting light on synthetic, SC-XRD and quantum mechanical studies for 2,1-benzothiazine based bis-adducts

A series of new bis-adducts, based on 2,1-benzothiazine 2,2-dioxide heterocyclic ring system were prepared. The precursor compound, 1-benzyl-2,1-benzothiazin-4(3H)one 2,2-dioxide was synthesized from methyl anthranilate through multistep reaction. It was reacted with various substituted benzaldehydes in the presence of triethylamine to get the titled series of bis-adducts. Among the series, 1-benzyl-3-((1-benzyl-4‑hydroxy-2,2-dioxido-1H-benzo[c][1,2]thiazin-3-yl) (4‑chloro phenyl) methyl)-1H-benzo[c][1,2]thiazin-4-olate 2,2-dioxide 6a was obtained in crystalline form as triethylammonium salt and was studied by XRD analysis. The compound was crystalized with triclinic crystal system where the α, β and γ angles are 103.374(5)°, 100.646(5)° and 111.736(6)° respectively. The structure elucidation of the synthesized compounds was carried out by NMR and MS techniques. The compound 6a was selected as representative molecule among a series of bis-adducts to understand electronic properties and structural parameters. For this, various sorts of DFT based analyses such as natural bond orbital (NBO), frontier molecular orbital (FMO), global reactivity parameters (GRPs), natural population analysis (NPA) and molecular electrostatic potential (MEP) of 6a were procured at ωB97XD level along with 6–31G(d,p) basis set. NBO approach provided perceptions regarding the stability and charge migration of 6a. Furthermore, 4.837 eV band gap of HOMO/LUMO was determined and the GRPs were also accomplished with the aid of FMO energies. The findings of GRPs and NBO analyses described the chemical stability of 6a. Color plotting scheme of MEP surfaces directed towards reactive sited of 6a in terms of nucleophilicity and electrophilicity.

Scalable Synthesis and Characterization of Multilayer γ-Graphyne, New Carbon Crystals with a Small Direct Band Gap.

γ-Graphyne is the most symmetric sp2/sp1 allotrope of carbon, which can be viewed as graphene uniformly expanded through the insertion of two-carbon acetylenic units between all the aromatic rings. To date, synthesis of bulk γ-graphyne has remained a challenge. We here report the synthesis of multilayer γ-graphyne through crystallization-assisted irreversible cross-coupling polymerization. A comprehensive characterization of this new carbon phase is described, including synchrotron powder X-ray diffraction, electron diffraction, lateral force microscopy, Raman spectroscopy, infrared spectroscopy, and cyclic voltammetry. Experiments indicate that γ-graphyne is a 0.48 eV band gap semiconductor, with a hexagonal a-axis spacing of 6.88 Å and an interlayer spacing of 3.48 Å, which is consistent with theoretical predictions. The observed crystal structure has an aperiodic sheet stacking. The material is thermally stable up to 240 °C but undergoes transformation at higher temperatures. While conventional 2D polymerization and reticular chemistry rely on error correction through reversibility, we demonstrate that a periodic covalent lattice can be synthesized under purely kinetic control. The reported methodology is scalable and inspires extension to other allotropes of the graphyne family.

PERBANDINGAN SIFAT OPTIK CDOTS BERBAHAN DAUN BINAHONG (ANREDERA SCANDES L.) SEGAR DAN KERING MENGGUNAKAN METODE BOTTOM UP

Carbon dots (Cdots) are synthesizable nanoparticles. One of them is taking advantage of binahong leaves (Anredera scandes L.). In this research, the synthesis of Cdots fresh binahong leaves and dried binahong leaves has been carried out. Using buttom up method and UV-Vis characterization. Microwave heating for 30 minutes. Meanwhile, the physical properties of the resulting Cdots color are fresh Binahong leaves showing a yellowish green color, while the physical properties of dry Binahong leaves show a brownish green color. Cdots fresh binahong leaves has a light absorbance spectrum at a wavelength of 200-800 nm with the highest intensity measured at a wavelength of 323 and the energy value of the band gap of 1.503 Ev. Meanwhile, for Cdots, dried Binahong leaves have a light absorption spectrum at a wavelength of 200-800 nm with the highest intensity measured at a wavelength of 361 nm and an energy value of 8.231 Ev band gap.

Green synthesis and biomedical behavior of Mg-doped ZnO nanoparticle using leaf extract of Ficus religiosa

Eco-friendly synthesis of Mg doped ZnO NPs was prepared by Ficus religiosa leaf extract. XRD confirmed the crystalline structure of the prepared Mg-doped ZnO. The functional groups and Zn and O bonding were realized from FTIR and Raman analyses. The surface plasma resonance absorption peak at 363 nm affirmed the formation of Mg–ZnO nanoparticles. The 3.32eV bandgap value of Mg–ZnO NPs was calculated by using Tauc's plot. The photoluminescence spectrum showed the emission behavior and point defect arising from zinc, oxygen vacancies. The hexagonal wurtzite structure of the prepared nanoparticles was observed from FESEM images. From the EDAX study, the elemental compositions have confirmed.The Thermal studies(TG/DTA)study,the Mg doped ZnO Material become thermally stable at 600 °C In XPS spectrum shows good formation of Mg doped ZnO nano materialThe facile synthesized Mg–ZnO NPs using Ficus religiosa leaves showed better antimicrobial properties on gram-positive bacterium, Staphylococcus aureus and fungus, Aspergillus niger . The biomedical behavior of prepared Mg–ZnO NPs was clearly understood from antioxidant(500 μg/mL-87), anti-inflammatory(500 μg/mL-89) and anti-diabetic assays(500μg/mL-82)

A Type-II WSe2/BP heterostructure with adjustable electronic properties under external electric field and biaxial strain

Through first-principles calculations, we investigate in detail the structural, electronic, and optical properties of the stable two-dimensional WSe2/BP van der Waals heteroplasms. Firstly, the effects of different stacking angles and defects on the stability and photoelectric properties of heterostructures were verified. Then the results of band structure show that 0.78eV bandgap and Type-II band alignment are formed at the WSe2/BP vdW heterogeneous double-layer interface, which is conducive to the effective separation of photogenerated electrons and holes. The WSe2/BP heterostructure shows a wide absorption spectrum in the visible region. In addition, the WSe2/BP heterostructure change from Type-II to Type-I band alignment and then to Type-II band alignment under different electric fields. The transformation of semiconductors to metal can also be observed under stronger electric fields. Moreover, the bandgap is effectively adjusted by the biaxial strain. Therefore, these properties make the WSe2/BP heterostructure promising for future optical detection.

Efficient Perovskite Indoor Photovoltaics with Open-Circuit Voltage of 1.15V via Collaborative Optimization of CsPbI2 Br Layer and Hole Transport Layer.

All-inorganic CsPbI2 Br perovskite has attracted great attention due to the stable crystal structure and moisture resistance, and its 1.91eV bandgap is close to the optimal bandgap of indoor artificial light sources, making it be the best candidate for the indoor photovoltaics (IPVs) to power a wide range of internet of things related electronic devices. Herein, we report on the preparation of CsPbI2 Br with α-phase and the improvement of its phase stability by adding lead acetate in the CsPbI2 Br precursor. A series of dopant-free conjugated polymers (P3HT, PBDB-T, and PM6) with different highest occupied molecular orbital energy levels are introduced as hole transport layers for building IPV devices. The PM6 based devices having better energy alignment with perovskite demonstrate best indoor photovoltaic performance, giving a remarkable open-circuit voltage of 1.15V and high fill factor of 81.86% under 1000 lux (330 µW cm-2 ) light-emitting diode illumination, and finally realizing a decent power conversion efficiency of 33.68%. Our findings suggest that collaboratively optimize the CsPbI2 Br layer and hole transport layer is an effective approach to realize high performance IPVs.

Deposition Mechanism and Characterization of Plasma-Enhanced Atomic Layer-Deposited SnOx Films at Different Substrate Temperatures.

The promising functional tin oxide (SnOx) has attracted tremendous attention due to its transparent and conductive properties. The stoichiometric composition of SnOx can be described as common n-type SnO2 and p-type Sn3O4. In this study, the functional SnOx films were prepared successfully by plasma-enhanced atomic layer deposition (PEALD) at different substrate temperatures from 100 to 400 °C. The experimental results involving optical, structural, chemical, and electrical properties and morphologies are discussed. The SnO2 and oxygen-deficient Sn3O4 phases coexisting in PEALD SnOx films were found. The PEALD SnOx films are composed of intrinsic oxygen vacancies with O-Sn4+ bonds and then transformed into a crystalline SnO2 phase with increased substrate temperature, revealing a direct 3.5–4.0 eV band gap and 1.9–2.1 refractive index. Lower (<150 °C) and higher (>300 °C) substrate temperatures can cause precursor condensation and desorption, respectively, resulting in reduced film qualities. The proper composition ratio of O to Sn in PEALD SnOx films near an estimated 1.74 suggests the highest mobility of 12.89 cm2 V−1 s−1 at 300 °C.

Activation of h‐BN and SiC monolayer sheets through foreign atom substitution; a comparative study based on ab‐initio method

AbstractHere, we studied two different 2D monolayer systems (i.e., h‐BN and SiC), which exhibit unique electronic and magnetic properties. We analyzed the effects of Transition Methods (TM) doped atoms (i.e., Mn, Ni, and Sc) on the single vacancy (SV) h‐BN and SiC systems using first principles calculations. Through comparison we found that Mn substitution in SV h‐BN and SiC can modify their electronic and magnetic properties having larger magnetic moment as compared to other dopants (i.e., Ni and Sc.). Band structure and PDOS plots confirmed that TM doping in SV h‐BN can convert the pure h‐BN (insulator) to semiconductor, metal, or semi‐metal, it is also observed from the results that Mn‐doped h‐BN has higher band gap approximately equal to Eg ~ 2.7 eV during the negative spin and has smaller band gap, that is, (Eg ~ 1.1 eV) during the positive spin. Similarly doping with the TM atoms on the SV SiC monolayer system can convert pure SiC to metal or half metal. In addition, Mn‐doped SiC showed semimetal property having 0 eV band gap. These finding will help us to vary the electronic and magnetic properties of the pure h‐BN and SiC sheets which can be used for the opto‐electronic and spintronic applications.

Investigation of the electronic structural and optical properties of CH3NH3HgI3 crystal

Based on the first-principles density functional theory, the electronic structure and optical properties of CH3NH3HgI3 crystal were investigated by means of generalized gradient approximation (GGA + U) approach. Then, CH3NH3HgI3 crystal was grown successfully by anti-solvent method, and the UV-vis-NIR spectra of crystal grown were investigated. The results indicate that CH3NH3HgI3 belongs to direct band-gap semiconductor with 2.801eV of band-gap. The energy level of electrons at the top of the valence band and the bottom of the conduction band is mainly formed by Hg and I, while C, N, and H of CH3NH3+ do not participate in forming the electron configuration near the Fermi level. CH3NH3HgI3 was combined by electrostatic interactions with CH3NH3+ and [HgI4]2-. Their electrostatic interactions lead to distortion of [HgI4]2- tetrahedron and cause the increase of band-gap of CH3NH3HgI3. Moreover, steric hindrance effect of CH3NH3+ spurs [HgI4]2- tetrahedron to form 1D chain structure. The result obtained from the UV-vis-NIR spectra of crystal shows that the band-gap of CH3NH3HgI3 crystal is 2.877eV, which is good coincident with the calculated gap (2.801eV). Our discussions on the electronic structural and energy band of crystal suggest that CH3NH3HgI3 can be used as an ultraviolet detector material.

Liquid crystal semiconductor C6TBTAPH2 for hole transport materials in pervoskite solar cells: Fabrication, characterization, and simulation

A study on efficient perovskite solar cells (PSCs) utilizing non-peripherally substituted octahexyltetrabenzotriazaporphyrin (C6TBTAPH2) hole transporting material (HTM) was demonstrated through fabrication, characterization, and simulation. C6TBTAPH2 semiconductor possesses a compatible energy band diagram (highest occupied molecular orbital energy levels of 5.17 eV and energy band gap of 1.59 eV) and a relatively high charge carrier mobility for a potential HTM in PSC. The simulated PSCs (using solar cell capacitance simulator – one dimensional programs) with C6TBTAPH2 HTMs exhibited the relatively high photovoltaic performance with power conversion efficiencies (PCEs) of 19.5%, but there existed a gap between the simulated and experimental data. Those differences were in part due to the low acceptor density of the pristine and/or p-type doped C6TBTAPH2 HTM and the parallel alignment of C6TBTAPH2 molecules on glass substrates. We suggest that C6TBTAPH2 semiconductor could be a potential HTM in PSC if the indications from the simulated results are well dealt with.