Photocurrent spectroscopic observation of interband transitions in GaAs-AlGaAs quantum wells under an applied high electric field

A438 weakly broadened subband structure of modulation-doped hetero-structure superlattices. Two different versions of such superlattices will be discussed. The first temperature-, intensity-, and time-dependent luminescence measurements on “type-11 hetero n-i-p-i’s” confirm the expected fine structure of the luminescence spectra. New non-linear optical phenomena like absorption oversaturation are predicted for “type-I hetero n-i-p-i’s”.

248

Surface

Science 174 (1986) 248-249 North-Holland, Amsterdam

TRANSIENT RESPONSE OF PHOTOLUMINESCENCE TO AN ELECTRIC FIELD IN A GaAs/Al,,,Ga,,As SINGLE QUANTUM WELL : EVIDENCE FOR FIELD-INDUCED INCREASE IN CARRIER LIFETIME Masamichi YAMANISHI, Yuichi USAMI, Yasuo KAN and Ikuo SUEMUNE Department of Physical Electronics, Higashi-Hiroshima 724, Japan Received

1 August

1985; accepted

Faculty

of Engineering

for publication

Hiroshima

9 November

Saijocho,

1985

Surface

250

University,

Science 174 (1986) 250-254 North-Holland, Amsterdam

PHOTOCURRENT SPECTROSCOPIC OBSERVATION OF INTERBAND TRANSITIONS IN GaAs-AIGaAs QUANTUM WELLS UNDER AN APPLIED HIGH ELECTRIC FIELD K. YAMANAKA, and M. ISHII Optoelectronics Received

T. FUKUNAGA,

Joint Research Laboratoq

2 August

1985; accepted

N. TSUKADA, 1333 Kamikodanaka,

for publication

12 November

K.L.I. Nakahara,

KOBAYASHI Kawasaki

211, Japan

1985

A technique using photocurrent spectroscopy under high electric field perpendicular to the heterointerface has been applied to characterize the interband transitions in 105 A thick GaAs/125 A thick AlGaAs multiple quantum wells (MQWs). The spectra from MQWs under high electric fields show various clear exciton peaks corresponding to forbidden transitions from heavy- and light-hole subbands to electron subbands. From both allowed and forbidden transition peaks, we determined the interband transition energies between the two lowest electron and four highest hole subbands, and the splitting energies of these subbands. Our data are in excellent agreement with a finite-square-well calculation using a conduction band offset of 60% of the band gap discontinuity, a heavy-hole effective mass of 0.34, and a light-hole effective mass of 0.12.