STUDY OF SURFACE PASSIVATION OF INP

The effects of various surface preparation procedures, including chemical treatments in HF, HNO3, o‐H3PO4 and H2SO4 solutions and anodic oxidation, on the passivating properties of InP have been investigated in order to optimize the fabrication procedures of n+p or p+n InP solar cells made by thermal diffusion. The InP substrates used in this study were p‐type Cd‐doped to a level of 1.7 × 1016 cm−3, Zn‐doped to levels of 2.2 × 1016 and 1.2 × 1018 cm−3 and n‐type S‐doped to 4.4 × 1018 cm−3. The passivating properties have been evaluated from photoluminescence (PL) data; good agreement was found between the level of surface passivation and the composition of different surface layers as revealed by x‐ray photoelectron spectroscopy (XPS) analysis. Copyright © 1990 John Wiley & Sons Ltd.