Characterization and photocurrent spectroscopy of single quantum wells

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459350· OSTI ID:6014960

Parsons, C A; Thacker, B R; Szmyd, D M; Peterson, M W; McMahon, W E; Nozik, A J ^[1]

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1. Solar Energy Research Institute, Golden, CO (USA)

GaAs/Al{sub {ital x}}Ga{sub 1{minus}{ital x}}As single quantum wells (SQWs) have been characterized by various spectroscopies and studied as electrodes in photoelectrochemical cells and in gold Schottky barrier structures. The techniques used were photoreflectance (PR), photoluminescence (PL), photocurrent (PC) spectroscopy, and impedance measurements. The energy level structure and well shape were best determined from PR data. The {ital p} doping of the buffer layer eliminated {ital p}--{ital n} junctions between the buffer layer and substrate and the inner Al{sub {ital x}}Ga{sub 1{minus}{ital x}}As barrier, thereby producing nearly ideal Mott--Schottky plots (no frequency dispersion or light dependence) so that the flatband potentials of these SQW electrodes could be well determined. Stark shifts in the PC spectra could also be seen if the buffer layer of the electrodes is doped {ital p} type. Very high quantum yields exhibited by SQW electrodes at room temperature with thick (270 A) Al{sub {ital x}}Ga{sub 1{minus}{ital x}}As barriers are explained by thermionic emission. At low temperatures with Schottky barriers, other mechanisms, such as tunneling, dominate. Hot photoluminescence spectra were also obtained and the hot carrier behavior of SQWs is compared with multiple quantum wells.

• OSTI ID: 6014960
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 93:11; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CHARGE CARRIERS
CURRENTS
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRIC CURRENTS
ELECTRIC IMPEDANCE
ELECTROCHEMICAL CELLS
ELECTRODES
EMISSION
EQUIPMENT
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
IMPEDANCE
LOSSES
LUMINESCENCE
PHOTOCURRENTS
PHOTOELECTRIC CELLS
PHOTOELECTROCHEMICAL CELLS
PHOTOLUMINESCENCE
PHOTOVOLTAIC CELLS
PNICTIDES
QUANTUM EFFICIENCY
RELAXATION
SCHOTTKY BARRIER SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
THERMIONIC EMISSION
TUNNELING