https://doi.org/10.15407/jopt.2018.53.013

Optoelectron. Semicond. Tech. 53, 13-37 (2018)

Kostylyov V.P., Sachenko A.V.

Semiconductor photovoltaics: сurrent state and actual directions of research

Recently, the work to improve the efficiency of solar energy photoconverters (SEPCs) has been continued, due to which the achieved efficiency values in the SEPC based on silicon are closely approached to their limit ones. Active researches in the field of semiconductor energy converters are being performed at the V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine. Therefore, this review outlines the upto-date state of researches in semiconductor photovoltaics. From the analysis of the distribution of the photovoltaics market, it has been concluded that the silicon technology will dominate in the next 10 to 15 years. The record values of the efficiency of SEPCs based on various materials are adduced. The features of the generation and recombination processes as well as the current passage in the SEPC based on both p-n- junctions and amorphous silicon / crystalline silicon (α-Si: H/c-Si) heterojunctions, in a wide range of excitation level changes are analyzed both for the limiting case, when the removable recombination mechanisms can be neglected, and for the real case, when all available recombination mechanisms are taken into account. It has been shown that, in the case of large lifetimes of non-equilibrium charge carriers and doping level of ~ 1015 cm–3 already in the AM1,5 (1000 W/cm2 ) conditions in the silicon SEPCs, a high excitation level is realized. When increasing the applied voltage, at 0.5 V< 0.7 V, the value of the non-ideality factor in current-voltage characteristics is also equal to 2, like to the case of recombination inside the space charge region, due to the effect of an isotypical barrier at the rear surface. An overview of the results of work on the development of physical and physico-technological basis for creation of highly efficient (efficiency up to 20%, AM1,5) multi-barrier SEPCs for space and terrestrial applications based on silicon multilayered structures with combined diffusion and induced barriers, SEPCs with rear barriers and contact metallization, concentrating SEPCs and installations on their basis, combined solar panels and wind turbine installation intended to power low-power equipment in extreme field conditions, performed at the V.Ye. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine.

Keywords: resources, solar energy, solar panels, photoconverter of solar energy, efficiency of the solar cell.