In:
MRS Proceedings, Springer Science and Business Media LLC, Vol. 668 ( 2001)
Abstract:
The observed junction between α-CuInSe 2 and the In-rich compositions in the β-phase domain (e.g. CuIn 3 Se 5 ) appears to play an important role in the photovoltaic process [1]. There remain, however, inconsistencies and uncertainties about the boundary and structure of this phase. In general the structure of this phase belongs to defect tetrahedral family of structures [2] , which can be described as normal tetrahedral structures with a certain fixed number of unoccupied structure sites. In this work, the local structures of various (Cu 2 Se) x (In 2 Se 3 ) 1−x semiconductor alloys in the β-phase domain were studied by Extended X-ray Absorption Fine Structure (EXAFS) and the results were compared to those for the α-CuInSe 2 phase. The long- range order of these compositions was studied by X-Ray powder Diffraction (XRD) and electron diffraction. It was found the local structures of these compounds are well defined. These compounds, however, could not be well described by any long-range order structure model, especially the selenium position. First-principles band structure calculations were performed to assist in assigning crystal structures to CuInSe 2 , CuIn 3 Se 5 and CuIn 5 Se 8 . The calculations indicated that the local environments of these compounds are well defined. Their long-range order might depend sensitively on growth history and the configurational entropies as suggested by the similar formation energies of several possible crystal structures for CuIn 3 Se 5 and CuIn 5 Se 8 .
Type of Medium:
Online Resource
ISSN:
0272-9172
,
1946-4274
DOI:
10.1557/PROC-668-H4.3
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2001
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