Solar RRL最新文献

Hydrogen Generation

Surface-modified TiO₂ with bimetallic AuPd nanoalloys exhibits high photocatalytic activity for hydrogen generation, this activity is close to that obtained with Pt-modified TiO₂. Experimental results are supported by density functional theory (DFT) and density functional tight binding (DFTB+) calculations, which show that alloying AuPd with low Pd content presents significant synergetic effects for hydrogen generation under UV-visible light. More in article number 2400106, José Luis Rodríguez-López, Hynd Remita, and co-workers.

Transparent photovoltaics (TPVs) are crucial for developing next-generation see-through electronics. However, TPV devices (TPVDs) require wide-bandgap materials that are typically only responsive to short wavelength (ultraviolet, UV) lights rather than visible lights. Is it possible to improve the TPV performance by harvesting the longer wavelength lights without degradation of transparency? It may be satisfied with the function of intermediate energy states, which can utilize the lower photon energy (longer wavelength light) by a two-step transition. To achieve this, co-sputtered Ti-doped ZnO (Ti:ZnO) film-based high-performance TPVDs have been developed. Density functional theory analysis revealed the formation of intermediate energy states due to the hybridization of O 2p and Ti 3d orbitals in the Ti:ZnO system. The Ti:ZnO-based TPVDs show 65% average visible transparency with a power production value of 655 μW cm⁻². These devices exhibit good photodetection behavior under UV to visible illuminations with high responsivity and detectivity values of 1.85 A W⁻¹ and 2.5 × 10¹³ Jones, respectively. Finally, a high-performance UV to visible broadband and wide-field-of-view photocommunication system is designed based on the TPVDs to generate the fast Morse code signal. Therefore, Ti doping in ZnO provides a good way to improve the device's functionality for futuristic applications.

The complicated trilateral relationships among molecular structures, properties, and photovoltaic performances of electron donor and acceptor materials hinder the rapid improvement of power conversion efficiency (PCE) of organic solar cells (OSCs). Herein, the database of 310 donor and non-fullerene acceptor pairs is constructed and 39 molecular structure descriptors are selected. Four kinds of machine learning (ML) algorithms random forest (RF), extra trees regression, gradient boosting regression trees, and adaptive boosting are applied to predict photovoltaic parameters. The coefficient of determination, Pearson correlation coefficient, mean absolute error, and root mean square error are adopted to evaluate ML performance. The results show that the RF model exhibits the best prediction accuracy. The Gini important analysis suggests the fused ring and aromatic heterocycles are critical fragments in determining PCE. The molecular unit sets are constructed by cutting each donor and acceptor molecules in database. The 31 752 D-π-A-π type donor molecules and 5 455 164 A-π-D-π-A type acceptor molecules are designed by recombination of molecular units, and 173 212 367 328 donor–acceptor pairs are generated by combining the newly designed donor and acceptor molecules. Based on the predicted PCE using the trained RF model, 42 donor–acceptor pairs exhibit the predicted PCE > 16%, in which the highest PCE is 16.24%.

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.

In this study, the internal and external stabilities of a p–i–n methylammonium lead iodide perovskite solar cell (PSC) are improved. Polystyrene (PS) is introduced into the perovskite layer to form a cross-linked polymer–perovskite network, which enhances the nucleation and growth of the perovskite grains. Moreover, for the first time, 60 nm thick ZnO/AlO_x nanolaminate (NL) thin-film encapsulation (TFE) is deposited directly on the PSC using an atmospheric-pressure (AP) spatial atomic layer deposition system operated in AP spatial chemical vapor deposition (AP–SCVD) mode. The rapid nature of AP–SCVD enables encapsulation of the PSCs in open air at 130 °C without damaging the perovskite. The PS additive improves the performance and internal stability of the PSCs by reducing ion migration. Both the PS additive and the ZnO/AlO_x NL TFEs improve the external stability under standard test conditions (dark, 65 °C, 85% relative humidity [RH]) by preventing water ingress. The number and thickness of the ZnO/AlO_x NL layers are optimized, resulting in a water–vapor transmission rate as low as 5.1 × 10⁻⁵ g m⁻² day⁻¹ at 65 °C and 85% RH. A 14-fold increase in PSC lifetime is demonstrated; notably, this is achieved using PS, a commodity-scale polymer, and AP–SCVD, a scalable, open-air encapsulation method.

Perovskite Solar Cells

In article number 2301078, Grace Dansoa Tabi, Thomas P. White, Daniel Walter, and co-workers used numerical device simulations to explore the performance potential of local contact structures in perovskite solar cells. They observed that nanometer-scale contacts are necessary for best performance, motivating self-forming techniques for effective local contact formation.

Silicon Heterojunction Solar Cells

In article number 2400052, Wenzhong Shen and co-workers fabricated industrial silicon heterojunction (SHJ) solar cells with an average efficiency of 25.18% and a 46% decline in Ag consumption with bifacial Ag/Cu fingers. Furthermore, the print qualification rate and high-temperature stability of SHJ solar cells with Ag/Cu fingers have been provided.

A crucial challenge in the development of semi-transparent solar cells is to maintain a reasonable power conversion efficiency (PCE) while reaching a high average visible transparency (AVT). Typically, organic semiconductors are favorable for this application since they can selectively absorb infrared light while transmitting visible light. This ability stems from limited electronic states at high(er) energies in contrast to inorganic semiconductors with their typical rise of the absorption coefficient toward higher photon energies. To increase PCE at high AVTs, a series of infrared dielectric Bragg reflectors is developed for semi-transparent organic solar cells. Using the multi-layered back electrode (TiO₂|SiN|TiO₂|AZO|Ag|AZO) with PV-X Plus as photoactive layer and a metal-free PEDOT:PSS top electrode, a light utilization efficiency (LUE = AVT × PCE) of up to 4.32% is achieved, together with an AVT of 47.9%. Although the short circuit current and AVT agree well with optical simulations, a low fill factor (FF) and partial shunting limit the overall device performance. Using ZnO and PFN-Br as additional electron transport layers and modifying the back electrode stack (TiO₂|SiO₂|TiO₂|AZO|Ag|AZO) accordingly leads to an LUE of up to 4.6% with a remarkable AVT of 51.9% and a maximum PCE of 8.79%.

As perovskite/silicon tandem solar cells head toward industrialization, one emerging challenge relates to the mechanical reliability of these organic–inorganic multilayer devices. Herein, the fracture toughness and interfacial strength of monolithic p–i–n perovskite/silicon tandems are assessed in the context of module integration. While the weakest layer in the tandem stack investigated is found to be C₆₀, used here as electron-transport layer (interfacial tensile strength of 0.64 MPa), more concerningly, the fracture energy of the C₆₀/tin-oxide interface is found to be only 1.2 J m⁻². The low fracture toughness of perovskite/silicon tandems can encourage crack propagation and large-scale delamination during processes used for their integration into modules such as cell cutting, interconnection, and vacuum lamination. By improving the tin oxide buffer layer properties and reducing sputtering-induced internal stress (associated with the transparent top electrode deposition onto the tin the oxide buffer layer), the fracture energy is improved to over 160 J m⁻². A second strategy to mitigate delamination due to the low fracture toughness of the cells is tailoring encapsulation and cell processing techniques specifically toward the perovskite/silicon tandem technology. In this work, a critical reliability issue, relevant for any perovskite-based optoelectronic technology requiring device packaging, is addressed.

Lead halide perovskites are well known for their exceptional photophysical and electronic properties, which have placed them at the forefront of challenging optoelectronic applications and solar-to-fuel conversion. However, their air/water instability, combined with their toxicity, is still a critical problem that has slowed down their commercialization. In this sense, bismuth-based halide derivatives attract much interest as a potentially safer, air-stable alternative. Herein, a novel Bi-based perovskite-inspired material, IEF-19 (IEF stands for IMDEA Energy Framework), which contains a bulky aromatic cation (1,5-diammonium naphthalene), is prepared. Additionally, an N-alkylation strategy is successfully employed to achieve four water-stable perovskite-inspired materials, which contains diammonium naphthalene cations that are tetra-alkylated by methyl, ethyl, propyl, and butyl groups. Moreover, computational studies are performed to gain a deeper understanding of the intrinsic structural stability and affinity of water molecules for Bi-based perovskite-inspired materials. Importantly, the air- and water-stable IEF-19-Et (i.e., stable at least 12 months under ambient conditions and 3 weeks in contact with water) is found to be an active photocatalyst for vapor-phase overall water splitting in the absence of any sacrificial agent under both ultraviolet–visible or simulated sunlight irradiation. This material exhibits an estimated apparent quantum yield of 0.08% at 400 nm, partially explained by its adequate energy band level diagram.