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Globally, energy demands are massive, and environmental issues are rising against our sustainability. To maximize the use of renewable energy sources, development of efficient energy storage systems is mandatory. Lithium-ion batteries (LIBs) play an indispensable role in powering portable devices and electric vehicles, due to their high specific capacity and long cycle life. Manganese oxide (Mn3O4) is an environmentally friendly anode active material with high theoretical specific capacity of 936 mAh g−1for applications in Li-ion cells.

MoOX has emerged as an effective hole-selective layer for Si based heterojunction solar cells on account of its high workfunction. The hole selectivity of MoOX is fundamentally different from other carrier selective films as it does not have an electron blocking energy barrier in form of conduction band offset with Si. Accordingly, much is unknown about the hole-selective nature of Si/MoOX junction with many unresolved puzzles. Here, through a combination of detailed modeling and experiments, we provide a coherent, calibrated, and comprehensive model to describe unique hole selective features of Si/MoOX junctions. The model accurately predicts the dark characteristics (ideality factor and reverse saturation current) and the open-circuit voltage of Si/MoOX based heterojunction solar cells reported in the literature. In addition, the same model anticipates the trends for solar cells with a-Si as interlayer passivation. As such this work establishes the limits of achievable VOC and its functional dependence on MoOX material parameters and, hence, could be of broad interest to enable further performance optimization of solar cells with large workfunction carrier selective layers such as V2O5 and WO3.

p-type Cu2O thin films doped with trivalent cation boron are demonstrated for the first time as an efficient hole-selective layer for c-Si heterojunction solar cells. Cu2O and Cu2O:B films were deposited by rf magnetron sputtering, and the optical and electrical properties of the doped and undoped films were investigated. Boron doping enhanced the carrier concentration and the electrical conductivity of the Cu2O film. The band alignment of the Cu2O:B/Si heterojunction was investigated using XPS and UPS measurements. The Cu2O:B/Si interface has a valance band offset of 0.08 eV, which facilitates hole transport, and a conduction band offset of 1.35 eV, which blocks the electrons. A thin SiOxtunnel oxide interlayer was also explored as the passivation layer. The initial trials of incorporating this Cu2O:B layer as a hole transporting layer in a single heterojunction solar cell with the structure, ITO/Cu2O:B/n-Si/Ag, and a cell area of 1 cm2yielded an open-circuit voltage of 370 mV, a short-circuit current density of 36.5 mA/cm2, and an efficiency of 5.4%. This p-type material could find potential applications in various optoelectronic applications like organic solar cells, TFTs, and LEDs.

Carrier selective (CS) Silicon solar cells are increasingly explored as a low-cost alternative to PN junction Silicon solar cells. While the recent trends on power conversion efficiency are encouraging, the temperature coefficient and hence the power output under elevated temperatures are not well explored for such solar cells. Here, we address this issue through detailed numerical simulations to explore the influence of interface and material parameters on the temperature coefficient. Our results indicate that irrespective of the interface quality, the temperature coefficient of CS solar cells improves with an increase in band discontinuities. Interestingly, contrary to the trends related to efficiency, our results indicate that the temperature coefficient of CS solar cells is more critically affected by the interface quality of the minority carrier extraction layer than the majority carrier extraction layer. These insights have important implications toward the choice of optimal material and processing conditions for Si-based CS solar cells

Transparent conducting, aluminium doped zinc oxide thin films ZnO:Al were deposited by radio frequency RF magnetron sputtering. The RF power was varied from 60 to 350 W whereas the substrate temperature was kept at 160 °C. The structural, electrical and optical properties of the asdeposited films were found to be influenced by the deposition power. The Xray diffraction analysis showed that all the films have a strong preferred orientation along the 001 direction. The crystallite size was varied from 14 to 36 nm, however no significant change was observed in the case of lattice constant. The optical band gap varied in the range 3.44–3.58 eV. The lowest resistivity of 1.2 × 10−3 Ω cm was shown by the films deposited at 250 W. The mobility of the films was found to increase with the deposition power.

Abstract: Highly conducting and transparent ZnO : Al thin films were grown by off-axis rf magnetron sputtering on amorphous silica substrates without any post-deposition annealing. The electrical and optical properties of the films deposited at various substrate temperatures and target to substrate distances were investigated in detail. Optimized ZnO : Al films have conductivity of 2200 S cm-1 and average transmission in the visible range is higher than 85%. The conductivity and mobility show very little temperature dependence.