Abstract
Thin films of CdTe1-xSx with bulk atomic compositions, x.ident.[S]/([S]+[Te]), ranging from 0 to 0.45 were deposited by vacuum co-evaporation of CdTe and CdS with substrate temperatures of 200 and 250 deg.C. X-ray diffraction analysis revealed that films with the <x <0.3 were predominately single phase having the zincblende structure. Films with 0.35<x<0.45 contained the wurtzite modification.Lattice parameter determination indicated that each phase exists with compositions well within the miscibility gap shown on published equilibrium phase diagrams. The variation of the optical band gap with x was determined by measuring transmission and reflection of the films. Heat treatment at 415 deg.C in the presence of CdCl2 caused the films to segregate into two phases consistent with thephase diagram. If the CdCl2 is assumed to only promote the phase segregation process, then the compositions of the two phases after heat treatment may be taken as measurements of the solubility limits of S in CdTe and Te in CdS respectively. The solubility limit of S in CdTe was thus determined to be 5.8% at 415 deg.C which is the temperature used for the common CdCl2 treatment of CdTe-basedsolar cells. An analysis of CdTe/CdS solar cell device structures shows that the atomic composition of alloys created by interdiffusion are consistent with these solubility limits.
Original language | American English |
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Pages | 325-330 |
Number of pages | 6 |
State | Published - 1996 |
Event | Thin Films for Photovoltaic and Related Device Applications: Materials Research Society Symposium - San Francisco, California Duration: 8 Apr 1996 → 11 Apr 1996 |
Conference
Conference | Thin Films for Photovoltaic and Related Device Applications: Materials Research Society Symposium |
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City | San Francisco, California |
Period | 8/04/96 → 11/04/96 |
Bibliographical note
Work performed by University of Delaware, Newark, DelawareNREL Publication Number
- NREL/CP-23034