Mg diffused zinc phosphide n/p junctions

Abstract

Heating a Mg/Zn₃P₂ Schottky solar cell in air results in the formation of an n/p junction due to the diffusion of Mg in Zn₃P₂. The cells are fabricated on large grain polycrystalline Zn₃P₂ wafers. The junction depth is determined from the change in the measured collection efficiency of the cell after heating and follows a (time)^1/2 dependence. The diffusion coefficient has been measured in the temperature range of 75–150 °C. The short‐circuit current and open‐circuit voltage of the homojunction qualitatively follow the theoretical predictions. A diffusion voltage of 1.2 V and a maximum open‐circuit voltage of 0.6 V have been achieved.