Carrier Transport Layers Research Articles

Reliability of transparent conductive oxide in ambient acid and implications for silicon solar cells

Transparent conductive oxide (TCO) films, known for their role as carrier transport layers in solar cells, can be adversely affected by hydrolysis products from encapsulants. In this study, we explored the morphology, optical-electrical properties, and deterioration mechanisms of In2O3-based TCO films under acetic acid stress. A reduction in film thickness and carrier concentration due to acid-induced corrosion was observed. X-ray photoelectron spectroscopy and inductively coupled plasma emission spectrometry analyses revealed that TCOs doped with less-reactive metals exhibited enhanced corrosion resistance. The efficiency of silicon heterojunction (SHJ) solar cells with tin-doped indium oxide, titanium-doped indium oxide, and zinc-doped indium oxide films decreased by 10%, 26%, and 100%, respectively, after 200 ​h of corrosion. We also found that tungsten-doped indium oxide could effectively safeguard SHJ solar cells against acetic acid corrosion, which offers a potential option for achieving long-term stability and lower levelized cost of solar cell systems. This research provides essential insights into selecting TCO films for solar cells and highlights the implications of ethylene-vinyl acetate hydrolysis for photovoltaic modules.

High performance wide bandgap perovskite solar cell with low VOC deficit less than 0.4 V

Wide bandgap perovskite solar cells (PSCs) have attracted significant attention because they can be applied to the top cells of tandem solar cells. However, high open-circuit voltage (VOC) deficit (>0.4 V) result from poor crystallization and high non-radiative recombination losses become a serious limitation in the pursuit of high performance. Here, the relevance between different PbI2 proportions and performance parameters are revealed through analysis of surface morphology, residual stress, and photostability. The increase of PbI2 proportion promotes crystal growth and reduces the work function of the perovskite film surface and promotes the energy level alignment with the carrier transport layer, which decreased the VOC deficit. However, residual PbI2 exacerbated the stress level of perovskite film, and the resulting lattice disorder deteriorated the photostability of the device. Ultimately, after the synergistic passivation of residual PbI2 and PEAI, the VOC achieves 1.266 V and VOC deficit is less than 0.4 V, the record value in wide bandgap PSCs.

Additive effect on hot carrier cooling in a hybrid perovskite.

Slowing hot carrier (HC) cooling in lead halide perovskites is important to further improve the efficiency of perovskite solar cells (PSCs). Herein, we found that HC cooling can be efficiently prolonged by incorporating an organic small molecule (TDGA) into the perovskite film as an additive through transient absorption spectroscopy measurements, which is conducive to the extraction of the HC energies by the carrier transport layers and reduces charge carrier recombination, consequently improving the efficiency of the TDGA-doped device.

Interfacial fixed charges and dipoles to boost carrier selectivity for crystalline silicon solar cells

<p>With the rapid evolution of passivating contact, the carrier transport layer in crystalline silicon (<i>c</i>-Si) solar cells has expanded beyond the doped silicon films to non-silicon films with lower parasitic absorption and manufacturing cost. However, using the emerging carrier transport layers in direct contact with <i>c</i>-Si suffers from the insufficient carrier selectivity, which limits the efficiency of the device. Thus, to make such new strategies practical, it becomes particularly important to enhance the passivation quality and thus minimize the recombination losses at <i>c</i>-Si surfaces. By introducing interfacial fixed charges (<i>Q</i><sub>f</sub>) or dipoles on the <i>c</i>-Si surface, the local electric field can be tuned to affect the recombination and charge carrier transport dynamics. This perspective highlights the significance of interfacial <i>Q</i><sub>f</sub> and dipoles for carrier selectivity, and points out the challenges in a comprehensive understanding of the mechanism and precisely controlling the carrier behavior as well as the solar cell stability.</p>

Influences of deposition conditions on atomic layer deposition films for enhanced performance in perovskite solar cells

Atomic layer deposition (ALD) is a key technology for fabricating functional layers in perovskite solar cells, as it can deposit pinhole-free films with atomic-level thickness and tunable composition on high-aspect-ratio surfaces. Various deposition conditions have significant effects on the growth, physical, and chemical properties of ALD films, which, in turn, critically influences the performance of associated devices. Here, we review the reaction mechanisms underlying ALD and summarize how variables, such as precursors, deposition temperatures, and substrates, impinge upon the quality of ALD films and the related devices. We emphasize the role of substrate in determining the nucleation and growth behavior of ALD films, which has been overlooked in previous reviews. Finally, we highlight the potential application of ALD in efficient perovskite solar cells in terms of carrier transport, encapsulated, and buffer layers, especially for tandem cells.

Unveiled effects of the methylammonium chloride additive on formamidinium lead halide: expediting carrier injection from the photoabsorber to carrier transport layers through spontaneously modulated heterointerfaces in perovskite solar cells

Time-resolved spectroscopies unveil the additional effects of the widely used methylammonium chloride (MACl) additive on FAPbI3 photoabsorber in perovskite solar cells, spontaneously modulating heterointerfaces for accelerating carrier injections.

Effect of Laser Type on Material Characteristics of Halide Perovskite Solar Cell Materials Fabricated Via Laser Molecular Beam Deposition

A key feature of halide perovskite solar cells is the ability to achieve conversion efficiencies in excess of 25% in a solution-coating process under atmospheric pressure [1, 2]. In the solution-coating process, equilibrium chemical reactions that promote crystal growth can produce thin films on the order of μm thickness in a few seconds. On the other hand, physical vapor deposition (PVD) has the advantage of controlled deposition at the molecular level of elements that cannot be obtained by solution reaction, although the deposition rate is relatively slow, generally from sub-nm/s to several tens of nm/s. Laser molecular beam deposition (LMBD), one of the PVD methods, can form thin films by heating and evaporation through infrared (IR) laser irradiation or by ablation through plasma formation by ultraviolet (UV) electron excitation with a pulsed UV laser. LMBD has the advantage of being able to switch the laser beam on and off only on the material surface, resulting in the instantaneous deposition of molecular layers of organic materials with high vapor pressure, as well as of high melting point materials such as inorganic oxides, with minimal cross-contamination. We have been developing halide perovskite solar cell materials based on these advantages in LMBD [3].Experiments with IR laser LMBD were conducted using the following process: synthetic quartz substrates were placed in an ultra-high vacuum chamber with a base vacuum of 2×10-5 Pa. A semiconductor continuous IR laser (wavelength: 808 nm) or an Nd:YAG Q-Switch quadruple-wave UV pulsed laser (wavelength: 266 nm, 10 Hz) was employed to alternately irradiate material targets of PbI2 and MAI, forming CH3NH3PbI3 (MAPbI3) at room temperature. The electron transport layer, using a TiO2 target, and the hole transport layer, using a CuI target, were formed at room temperature. The optical, crystalline, and electrical properties of the films were then characterized by UV-visible spectroscopy, X-ray diffraction (XRD), and Hall measurements, respectively.Four multilayer samples consisting of [PbI2/MAI]×n (n=1, 2, 5, 10) were prepared by IR-LMBD under conditions where the total thickness of PbI2 was fixed at 300 nm. The analysis of the prepared samples by XRD measurements revealed two distinct features: (1) The sample with n = 1 had unreacted PbI2 in addition to MAPbI3, while the samples with n = 2, 5, and 10 only showed MAPbI3, indicating a successful solid-phase reaction. (2) The full width at half maximum and peak position of the diffraction peak for MAPbI3 at 2θ = 14.0° ~ 14.1° varied among the samples, and thus peak separation was performed to determine the presence of both tetragonal (002) and orthorhombic (020) diffraction peaks.In UV-LMBD (or pulsed laser deposition; PLD), a deposition rate of 20 nm/s was attained for the perovskite layer, even under low fluence conditions without lens focusing. However, under the high fluence condition with the lens focusing, the deposition rate dropped significantly to about 0.35 nm/s. The evaluation of the film surface roughness suggested that the effective deposition rate was considerably reduced under the high fluence condition with lens-focusing, due to the excess kinetic energy of the film precursor, which caused re-sputtering on the film surface during deposition.The carrier transport layers were also fabricated by UV-LMBD. The optical and electrical properties of the TiO2 thin film fabricated as the electron transport layer showed an average optical transmittance of 85% and conductivity of 3.2 S/cm at 400 to 800 nm. The CuI thin film fabricated as the hole transport layer was found to have <111> preferential orientation of polycrystalline γ-CuI from the results of X-ray diffraction measurement and to display a conductivity of 24.5 S/cm, hole concentration of 2.7×1019 cm-3, and hole mobility of 6.0 cm2/ (V·s) in hole measurements.We are currently optimizing the process for consistently fabricating the electron transport layer, halide perovskite layer, and hole transport layer in a vacuum through pattern fabrication using a movable shielding mask in the film fabrication area of each layer.[1] T. Miyasaka, A. Kulkarni, G. M. Kim, S. Öz and A. K. Jena, Adv. Energy Mater. 2020, 11902500 (2020).[2] M. Green, E. Dunlop, G. Siefer, M. Yoshita, N. Kopidakis, K. Bothe, X. Hao, Progress in Photovoltaics 31, 3 (2023).[3] K. Kawashima, Y. Okamoto, O. Annayev, N. Toyokura, R. Takahashi, M. Lippmaa, K. Itaka, Y. Suzuki, N. Matsuki and H. Koinuma, Sci. Technol. Adv. Mater. 18, 307 (2017).

Numerical Simulation and Design of All-Thin-Film Homojunction Perovskite/c-Si Tandem Solar Cells

Double-junction solar devices featuring wide-bandgap and narrow-bandgap sub-cells are capable of boosting performance and efficiency compared to single-junction photovoltaic (PV) technologies. To achieve the best performance of a double-junction device, careful selection and optimization of each sub-cell is crucial. This work presents the investigation of an all-thin-film two-terminal (2T) monolithic homojunction perovskite (PVK)/c-Si tandem cell using Silvaco TCAD simulation. The front sub-cell utilizes homojunction PVK that has a bandgap of 1.72 eV, whereas the rear sub-cell uses thin c-Si with a bandgap of 1.12 eV. Both cells are connected via a p++/n++ silicon tunnel diode. Experimental calibration of the heterojunction PVK and c-Si cells yields power conversion efficiencies (PCE) of 18.106% and 17.416%, respectively. When integrated into an initial PVK/c-Si tandem, the resulting cell achieves a PCE of 29.38%. To compare the performance, the heterojunction PVK layer is replaced with an n-p homojunction PVK layer, revealing the impact of the absence of a surplus built-in electric field in the perovskite film as a strong limiting factor. Further, a thorough investigation of four distinct structures for the n-p homojunction PVK cell is conducted. The four structures include a complete cell, electron transport layer (ETL)-free, hole transport layer (HTL)-free, and carrier transport layer (CTL)-free structures. The results show that the CTL-free structure has significant potential after applying certain optimization techniques that result in reducing surface recombination, enhancing the built-in electric field, and improving light absorption. With the current-matching condition achieved, the tandem efficiency reaches 36.37%.

Advances in Hole Transport Materials for Layered Casting Solar Cells.

Huge energy consumption and running out of fossil fuels has led to the advancement of renewable sources of power, including solar, wind, and tide. Among them, solar cells have been well developed with the significant achievement of silicon solar panels, which are popularly used as windows, rooftops, public lights, etc. In order to advance the application of solar cells, a flexible type is highly required, such as layered casting solar cells (LCSCs). Organic solar cells (OSCs), perovskite solar cells (PSCs), or dye-sensitive solar cells (DSSCs) are promising LCSCs for broadening the application of solar energy to many types of surfaces. LCSCs would be cost-effective, enable large-scale production, are highly efficient, and stable. Each layer of an LCSC is important for building the complete structure of a solar cell. Within the cell structure (active material, charge carrier transport layer, electrodes), hole transport layers (HTLs) play an important role in transporting holes to the anode. Recently, diverse HTLs from inorganic, organic, and organometallic materials have emerged to have a great impact on the stability, lifetime, and performance of OSC, PSC, or DSSC devices. This review summarizes the recent advances in the development of inorganic, organic, and organometallic HTLs for solar cells. Perspectives and challenges for HTL development and improvement are also highlighted.

Investigating the Performance of Efficient and Stable Planer Perovskite Solar Cell with an Effective Inorganic Carrier Transport Layer Using SCAPS-1D Simulation

Organic–inorganic metal halide perovskite (OIMHP) has emerged as a promising material for solar cell application due to their outstanding optoelectronics properties. The perovskite-based solar cell (PSC) demonstrates a significant enhancement in efficiency of more than 20%, with a certified efficiency rating of 23.13%. Considering both the Shockley limit and bandgap, there exists a substantial potential for further efficiency improvement. However, stability remains a significant obstacle in the commercialization of these devices. Compared to organic carrier transport layers (CTLs), inorganic material such as ZnO, TiO2, SnO2, and NiOX offer the advantage of being deposited using atomic layer deposition (ALD), which in turn improves the efficiency and stability of the device. In this study, methylammonium lead iodide (MAPbI3)-based cells with inorganic CTL layers of SnO2 and NiOX are simulated using SCAPS-1D software. The cell structure configuration comprises ITO/SnO2/CH3NH3PbI3/NiOX/Back contact where SnO2 and NiOX act as ETL and HTL, respectively, while ITO is a transparent front-end electrode. Detailed investigation is carried out into the influence of various factors, including MAPbI3 layer size, the thickness of CTLs, operating temperature parasitic resistance, light intensity, bulk defects, and interfacial defects on the performance parameters. We found that the defects in layers and interface junctions greatly influence the performance parameter of the cell, which is eliminated through an ALD deposition approach. The optimum size of the MAPbI3 layer and CTL was found to be 400 nm and 50 nm, respectively. At the optimized configuration, the PSC demonstrates an efficiency of 22.13%, short circuit current (JSC) of 20.93 mA/m2, open circuit voltage (VOC) of 1.32 V, and fill factor (FF) of 70.86%.

A CTL-free homo-heterojunction antimony chalcogenide solar cell: Theoretical study

Exploring antimony chalcogenide as photovoltaic (PV) absorber material for solar cell is an appealing strategy. However, the conversion efficiency (η) of antimony chalcogenide solar cells including antimony selenide (Sb2Se3), antimony sulfide (Sb2S3) and antimony sulfide–selenide (Sb2(S,Se)3) lag far behind their Shockley−Queisser limit efficiency. Generally, the device PV performance of thin film heterojunction solar cells is mainly affected by the material properties of each functional layer, as well as the device architecture and heterointerface characteristics. Herein, a novel homo-heterojunction antimony chalcogenide solar cell without any carrier transport layer (CTL) consisting of FTO/(n)Sb2Se3/(p)Sb2Se3/(p)Sb2S3/Metal has been proposed. The influence of thickness, doping concentration and bulk defect density of the functional layer materials, the interface defect density at (p)Sb2Se3/(p)Sb2S3 heterointerfaces, and back contact metal work function on device PV performance have been theoretically analyzed utilized wxAMPS software. After optimization, the proposed solar cell has an open-circuit voltage (Voc) of 0.885 V, a short-circuit current density (Jsc) of 36.14 mAcm−2, a filling factor (FF) of 84.30 %, and a η of 26.97 %. These results indicate that the novel homo-heterojunction antimony chalcogenide solar cell without any CTL have the potential to become a high-efficiency PV device.

High Quantum Yield Sensitization of Single Crystal TiO2 Electrodes with CsPbBr3 Nanocrystals

Abstract Lead halide perovskites are promising materials for solar cells and photodetectors. Nanocrystals of this family of perovskites also have distinct properties. In this study we report the attainment of high quantum yield sensitized photocurrents from stabilized CsPbBr3 perovskite nanocrystals thermally evaporated onto doped single crystal rutile (110) TiO2 electrodes. Sensitized photocurrent stabilization was achieved by capping the nanocrystals with a thin NiOx layer and Au carrier transport and protection layers respectively as well as the judicious choice of solvent and electrolyte.

High performance broadband photodetector in two-dimensional metal dichalcogenides mediated by topologically protected surface state

Carrier scattering in photodetectors employing 2D dichalcogenide as an absorber impedes carrier transport. As scattering at the interface between the semiconductor and the electrode restricts carrier transport, it is essential to develop alternative electrode materials to achieve high photoresponsivity. A carrier can effectively move through a topologically protected Dirac surface state without scattering: i.e., alternatives such as topological insulators (TI) containing the surface state can effectively reduce scattering at the interface between the semiconductor and the electrode. In this stucy, TI Bi2Se3 with a well-ordered interfacial structure was used as a carrier transport layer (CTL) to effectively employ the topological surface state (TSS) for improving WSe2 photoresponsivity. At 520 nm, the Bi2Se3 TI-CTL photodetector has a photoresponsivity of up to 11.47 AW−1, 100 times higher than the photodevice using only Au electrodes. The photoresponsivity and time-resolved photoluminescence as a function of thickness indicate that TSS contributes to improved carrier separation with high carrier transfer efficiency, thereby affecting photocurrent generation. The fast carrier transfer through TSS helps efficiently separate electron-hole pairs and suppress recombination at the interface, generating ultra-fast and high-efficiency photocurrents in the broadband region (450–1550 nm). Therefore, TSS based on carrier dynamics can lead to further applications of next-generation optoelectronic devices.

Pyro-Phototronic Effect in All-Inorganic Two-Dimensional Ruddlesden-Popper Ferroelectric Perovskite Thin-films and Photodetection.

Ferroelectric perovskites, where ferroelectricity is embedded in the structure, are being considered for different device applications. In this study, we introduce Cs2PbI2Cl2, an all-inorganic 2D Ruddlesden-Popper (RP) halide perovskite, as a ferroelectric material suitable for pyro-phototronic applications. Thin-films of the all-inorganic perovskite are successfully cast, and they demonstrate ferroelectric properties. Unlike hybrid materials, the ferroelectricity in Cs2PbI2Cl2 does not rely on the organic moiety possessing an electric dipole moment. Instead, the 2D-layer-forming octahedra are twisted and tilted due to a distortion in the bond lengths, leading to the emergence of spontaneous electric polarization. Based on the properties, we fabricate p-i-n heterojunctions by integrating the perovskite with carrier-transport layers. To determine the band-energies of the materials, scanning tunneling spectroscopy and Kelvin probe force microscopy are employed. The band-edges evidence a type-II band-alignment at both interfaces, enabling the material to exhibit both photovoltaic and pyroelectric behaviors when subjected to pulsed illumination. The devices based on the all-inorganic RP perovskite developed in this study exhibit pyro-phototronic effects and serve as self-powered photodetectors without any need for an external bias.

Performance improvement of CZTS-based hybrid solar cell with double hole transport layer using extensive simulation

The extensive outcomes of the specific modeling method for hybrid photovoltaic solar cells at the illumination condition of AM 1.5G spectrum are shown in this simulation work. This research aims to optimize the efficiency of the device structures by introducing the novel hybrid-absorber layer (AL). The hybrid solar cell (HSC) has higher efficiency with an absorber layer (AL), i.e., Copper Zinc Tin Sulphide. The current simulation uses ZnO, V2O5, and Spiro-OMeTAD as the carrier transport layers (CTLs); both hole/electron transport layer (HTL/ETL) to sandwich the CZTS, which have precise bandgaps of 1.5 eV. Using double HTLs of Spiro-OMeTAD/V2O5 offers a high efficiency of 23.21%. The detailed examination of thickness, total defect density (DD), temperature dependency, and impedance-capacitance analysis of the simulated device structures are also studied simultaneously.

Cs2TiI6 (Cs2TiIxBr6-x) Halide Perovskite Solar Cell and Its Point Defect Analysis.

This work presents a comprehensive numerical study for designing a lead-free, all-inorganic, and high-performance solar cell based on Cs2TiI6 halide perovskite with all-inorganic carrier transport layers. A rigorous ab initio density-functional theory (DFT) calculation is performed to identify the electronic and optical properties of Cs2TiI6 and, upon extraction of the existing experimental data of the material, the cell is designed and optimized to the degree of practical feasibility. Consequently, a theoretical power conversion efficiency (PCE) of 21.17% is reported with inorganic TiO2 and CuI as carrier transport layers. The calculated absorption coefficient of Cs2TiI6 reveals its enormous potential as an alternative low-bandgap material for different solar cell applications. Furthermore, the role of different point defects and the corresponding defect densities on cell performance are investigated. It is found that the possible point defects in Cs2TiI6 can form both the shallow and deep defect states, with deep defect states having a prominent effect on cell performance. For both defect states, the cell performance deteriorates significantly as the defect density increases, which signifies the importance of high-quality material processing for the success of Cs2TiI6-based perovskite solar cell technology.

Perovskite Solar Cell Using Isonicotinic Acid as a Gap-Filling Self-Assembled Monolayer with High Photovoltaic Performance and Light Stability.

High photovoltaic performance and light stability are required for the practical outdoor use of lead-halide perovskite solar cells. To improve the light stability of perovskite solar cells, it is effective to introduce a self-assembled monolayer (SAM) between the carrier transport layer and the perovskite layer. Several alternative approaches in their molecular design and combination with multiple SAMs support high photovoltaic conversion efficiency (PCE). Herein, we report a new structure for improving both PCE and light stability, in which the surface of an electron transport layer (ETL) was modified by combining a fullerene-functionalized self-assembled monolayer (C60SAM) and a suitable gap-filling self-assembled monolayer (GFSAM). Small-sized GFSAMs can enter the gap space of the C60SAM and terminate the unterminated sites on the ETL surface. The best GFSAM in this study was formed using an isonicotinic acid solution. After a light stability test for 68 h at 50 °C under 1 sun illumination, the best cell with C60SAM and GFSAM showed a PCE of 18.68% with a retention rate of over 99%. Moreover, following outdoor exposure for six months, the cells with C60SAM and GFSAM exhibited almost unchanged PCE. From the valence band spectra of the ETLs obtained using hard X-ray photoelectron spectroscopy, we confirmed a decrease in the offset at the ETL/perovskite interface owing to the additional GFSAM treatment on the C60SAM-modified ETL surface. Time-resolved microwave conductivity measurements demonstrated that the additional GFSAM improved electron extraction at the C60SAM-modified ETL/perovskite interface.

Effects of Carrier Transport Layers on Performance Degradation in Perovskite Solar Cells under Proton Irradiation

Perovskite solar cells (PSCs) are potentially ideal for use in space satellites and spacecraft. While perovskites were found to be robust to space particle irradiations, it is important to investigate the influences of the carrier transport layers in PSCs on the irradiation-induced performance degradation. This study reports on the responses of different CsMAFAPbI3-based PSCs to 250 keV proton irradiation. Spiro-OMeTAD is used as a hole transport material in the cells, whereas SnO2, TiO2, and In2O3 are used as electron transport materials. After irradiation, the three different cells are not degraded up to 1 × 1013 p/cm2 and follow a similar degradation trend with further increasing the proton fluence until they are completely destroyed at 6 × 1014 p/cm2. By means of recycling, it is shown that SnO2, TiO2, and In2O3 have little influence on cell degradation, although the square resistances of SnO2, TiO2, and In2O3 on FTO/glass substrates are increased by 15–19% after irradiation of 6 × 1014 p/cm2; instead, the degradation of the spiro-OMeTAD material accounts for the reduced performance of the PSCs. The proton irradiation leads to a de-doping effect of spiro-OMeTAD, causing an efficiency decrease of the PSCs. A more radiation-resistant hole transport material to replace spiro-OMeTAD is therefore warranted to extend the lifetime of the PSCs in space environments.

Proposal and Numerical Analysis of Organic/Sb2Se3 All-Thin-Film Tandem Solar Cell.

The low bandgap antimony selenide (Sb2Se3) and wide bandgap organic solar cell (OSC) can be considered suitable bottom and top subcells for use in tandem solar cells. Some properties of these complementary candidates are their non-toxicity and cost-affordability. In this current simulation study, a two-terminal organic/Sb2Se3 thin-film tandem is proposed and designed through TCAD device simulations. To validate the device simulator platform, two solar cells were selected for tandem design, and their experimental data were chosen for calibrating the models and parameters utilized in the simulations. The initial OSC has an active blend layer, whose optical bandgap is 1.72 eV, while the initial Sb2Se3 cell has a bandgap energy of 1.23 eV. The structures of the initial standalone top and bottom cells are ITO/PEDOT:PSS/DR3TSBDT:PC71BM/PFN/Al, and FTO/CdS/Sb2Se3/Spiro-OMeTAD/Au, while the recorded efficiencies of these individual cells are about 9.45% and 7.89%, respectively. The selected OSC employs polymer-based carrier transport layers, specifically PEDOT:PSS, an inherently conductive polymer, as an HTL, and PFN, a semiconducting polymer, as an ETL. The simulation is performed on the connected initial cells for two cases. The first case is for inverted (p-i-n)/(p-i-n) cells and the second is for the conventional (n-i-p)/(n-i-p) configuration. Both tandems are investigated in terms of the most important layer materials and parameters. After designing the current matching condition, the tandem PCEs are boosted to 21.52% and 19.14% for the inverted and conventional tandem cells, respectively. All TCAD device simulations are made by employing the Atlas device simulator given an illumination of AM1.5G (100 mW/cm2). This present study can offer design principles and valuable suggestions for eco-friendly solar cells made entirely of thin films, which can achieve flexibility for prospective use in wearable electronics.

CsPbBr3 Quantum Dots‐Sensitized Mesoporous TiO2 Electron Transport Layers for High‐Efficiency Perovskite Solar Cells

Perovskite Solar Cells In article number 2300072, Michael Grätzel, Jingshan Luo, and co-workers show that the carrier transport layer plays a critical role in high-efficiency and stable perovskite solar cells (PSCs). They developed CsPbBr3 quantum dots sensitized mesoporous TiO2 (CPB-TiO2), which enhances perovskite crystallinity, phase stability, and reduces the non-radiative carrier recombination in PSCs. As a result, the CPB-TiO2 significantly improves the power conversion efficiency of FAPbI3 PSCs from 23.11% to 24.46%.