Optimization of doping design for planar P-N homologous junction perovskite solar cells

In this study, we used the solar cell capacitance simulator (SCAPS) to analyse numerically the performance of perovskite solar cells (PSCs) containing CH3NH3PbI3. The findings indicate that P-N homologous junction processing based on traditional P-I-N PSCs can enhance the photoelectric conversion efficiency (PCE). Furthermore, the authors analyzed the effect of uniform P-N doping of CH3NH3PbI3, concluding that the photoelectric efficiency can be improved from 16.10% to 19.03% after doping. In addition, the optical properties of PSCs under solar irradiation are simulated using finite difference time-domain (FDTD) software under AM1.5. This method is applied to investigate the effect of the P-N uniform junction on the internal electric field generated within the cell. The generation of this electric field promotes carrier separation and transmission, ultimately increasing the open circuit voltage (VOC) of the solar cell from 1.03 to 1.12 V. The usage of P-N junctions enhances PSCs performance and exhibits vast potential for designing and developing PSCs.

Ab Initio Screening of Doped Mg(AlH4)2 Systems for Conversion-Type Lithium Storage

In this work, we have explored the potential applications of pure and various doped Mg(AlH₄)₂ as Li-ion battery conversion electrode materials using density functional theory (DFT) calculations. Through the comparisons of the electrochemical specific capacity, the volume change, the average voltage, and the electronic bandgap, the Li-doped material is found to have a smaller bandgap and lower average voltage than the pure system. The theoretical specific capacity of the Li-doped material is 2547.64 mAhg⁻¹ with a volume change of 3.76% involving the electrode conversion reaction. The underlying reason for property improvement has been analyzed by calculating the electronic structures. The strong hybridization between Lis-state with H s-state influences the performance of the doped material. This theoretical research is proposed to help the design and modification of better light-metal hydride materials for Li-ion battery conversion electrode applications.

High-Mobility p-Type and n-Type Copper Nitride Semiconductors by Direct Nitriding Synthesis and In Silico Doping Design

Thin-film photovoltaics (PV) have emerged as a technology that can meet the growing demands for efficient and low-cost large-scale cells. However, the photoabsorbers currently in use contain expensive or toxic elements, and the difficulty in bipolar doping, particularly in a device structure, requires elaborate optimization of the heterostructures for improving the efficiency. This study shows that bipolar doping with high hole and electron mobilities in copper nitride (Cu₃ N), composed solely of earth-abundant and environmentally benign elements, is readily available through a novel gaseous direct nitriding reaction applicable to uniform and large-area deposition. A high-quality undoped Cu₃ N film is essentially an n-type semiconductor, while p-type conductivity is realized by interstitial fluorine doping, as predicted using density functional theory calculations and directly proven by atomically resolved imaging. The synthetic methodology for high-quality p-type and n-type films paves the way for the application of Cu₃ N as an alternative absorber in thin-film PV.