Title :
Reduced radiative currents from GaAs/InGaAs and AlGaAs/GaAs p-i-n quantum well devices
Author :
Nelson, J. ; Ballard, I. ; Barnes, J. ; Ekins-Daukes, N. ; Barnham, K.W.J. ; Kluftinger, B.G. ; Tsui, E.S.M. ; Foxon, C.T. ; Cheng, T.S. ; Roberts, J.S.
Author_Institution :
Blackett Lab., Imperial Coll. of Sci., Technol. & Med., London, UK
fDate :
29 Sep-3 Oct 1997
Abstract :
Calibrated electroluminescence spectra of GaAs/InGaAs and AlGaAs/GaAs single and double quantum well (QW) p-i-n devices, at various temperatures (200-300 K) and biases (0.8-1.5 V), have been compared to theory to extract the quasi-Fermi level separation, Δφf, in the QWs and where possible in the host material. Emission from the host material for the GaAs/InGaAs cell is well fitted with Δφf=Vapp at all biases and temperatures. In contrast, emission from the QW in both GaAs/InGaAs and AlGaAs/GaAs cases requires a value of Δφf which is a few tens of meV less than Vapp. We attribute the variations in Δφf to irreversible thermally assisted escape from the QWs and detail some preliminary results from double QW samples
Keywords :
Fermi level; III-V semiconductors; aluminium compounds; electroluminescence; gallium arsenide; indium compounds; semiconductor quantum wells; solar cells; 0.8 to 1.5 V; 200 to 300 K; AlGaAs-GaAs; AlGaAs/GaAs p-i-n quantum well devices; GaAs-InGaAs; GaAs/InGaAs p-i-n quantum well devices; double quantum well p-i-n devices; host material emission; irreversible thermally assisted escape; quasi-Fermi level separation; reduced radiative currents; single quantum well p-i-n devices; solar cells; Educational institutions; Electroluminescent devices; Gallium arsenide; Indium gallium arsenide; Laboratories; PIN photodiodes; Photovoltaic cells; Radiative recombination; Solid state circuits; Temperature measurement;
Conference_Titel :
Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE
Conference_Location :
Anaheim, CA
Print_ISBN :
0-7803-3767-0
DOI :
10.1109/PVSC.1997.654237
