Title :
Recombination effects at oxygen related double acceptors in Al0.10Ga0.90As
Author :
Ahrenkiel, R.K. ; Zhang, J. ; Keyes, B.M. ; Asher, S.E. ; Timmons, M.L.
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
Abstract :
AlxGa1-xAs is an important component of many high-efficiency photovoltaic devices. This work shows that the hole lifetime of n-type Al0.10Ga0.90As is controlled by impurity-oxygen-related recombination centers with capture cross sections of about 10-12 cm2 when the films are grown at temperatures of 720°C and lower. Correlated time-resolved photoluminescence and deep level transient spectroscopy measurements link these centers to well known impurity oxygen complexes. Film growth at temperatures above about 720°C eliminates these oxygen complexes from the epitaxial layer resulting in greatly improved photovoltaic properties
Keywords :
CVD coatings; III-V semiconductors; aluminium compounds; carrier lifetime; deep level transient spectroscopy; electron-hole recombination; gallium arsenide; impurity electron states; oxygen; photoluminescence; semiconductor epitaxial layers; semiconductor growth; semiconductor thin films; solar cells; vapour phase epitaxial growth; 720 C; Al0.10Ga0.90As; AlGaAs; O2; capture cross sections; correlated time-resolved photoluminescence; deep level transient spectroscopy measurements; epitaxial layer; film growth; impurity oxygen complexes; impurity-oxygen-related recombination centers; oxygen related double acceptors; photovoltaic devices; photovoltaic properties; solar cells; Electron traps; Fabrication; MOCVD; Oxygen; Photoluminescence; Photovoltaic systems; Solar power generation; Spectroscopy; Spontaneous emission; Temperature;
Conference_Titel :
Photovoltaic Specialists Conference, 1993., Conference Record of the Twenty Third IEEE
Conference_Location :
Louisville, KY
Print_ISBN :
0-7803-1220-1
DOI :
10.1109/PVSC.1993.347003
