Heteroepitaxy of CuIn/sub x/Se/sub y/ of Si and PbSe/CaF/sub 2//Si substrates

Abstract

Heteroepitaxial CuInSe/sub 2/, CuIn/sub 2/Se/sub 3.5/ and CuIn/sub 3/Se/sub 5/ (CuIn/sub x/Se/sub y/) layers have been directly grown on Si(111) substrates by molecular beam epitaxy in order to study their performance as CdS/CIS (single crystal) thin film solar cells. Reflection high energy electron diffraction was used to study the growth kinetics. (112)-oriented epitaxial layers free from impurity phases have been obtained. The positions of (448) X-ray diffraction peaks and vibrational mode frequencies of Raman spectra are used to identify different CuIn/sub x/Se/sub y/ phases. Rutherford backscattered ion channeling minimum yields of about 12% and 20% have been measured for about 0.5 /spl mu/m thick CuInSe/sub 2/ and CuIn/sub 3/Se/sub 5/ layers, respectively.