The efficiency of solar energy conversion by the CdS/por-Si/p-Si heterostructure: the dopant effect

摘要

In this paper, the effect of the distribution profile of the doping acceptor impurity concentration in the base region of the CdS/por-Si/p-Si heterostructure on the efficiency of solar energy conversion parameters has been studied. It was established that the solar energy conversion efficiency depended on the degree of a doping acceptor impurity depletion of the near-surface p-Si layer in the por-Si/p-Si heterojunction. The distribution profile of the impurity concentration in this space is formed during the growth of a porous silicon layer. This profile is controlled through changing the technological parameters of the process of a porous film growing: the current density and the duration time of the electrochemical etching. A gain in the conversion efficiency of solar energy was explained by an increase in the penetration depth of the electric field into the base region due to formation of a certain type of the impurity concentration distribution profile. In the final, this profile promotes the rapid carry-away of charge carriers generated by the light from the base region. This carry-away occurs before the carrier recombination moment involving traps.