Aa. Chowdhury et al., ROOM-TEMPERATURE OBSERVATION OF PHOTOCURRENT DEPENDENCE ON APPLIED BIAS IN SI1-XGEX SI MULTIQUANTUM WELLS/, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 11(4), 1993, pp. 1685-1688
We report the observation of the dependence of photocurrent on applied
bias in Si1-xGex/Si multiquantum wells at room temperature. The photo
currents were measured on reverse biased p-i-n diodes containing an in
trinsic region comprised of Si1-xGex/Si multiquantum wells. These Si1-
xGex/Si multiquantum wells were grown by the remote plasma enhanced ch
emical vapor deposition method. Using the technique employed by Park e
t al. [J. Vac. Sci. Technol. B 8, 217 (1990)] to analyze similar exper
imental observations at lower temperature (77 K), we have estimated th
e absorption edges from the photocurrents and showed a large transitio
n energy shift under electric field. The observed shape of the absorpt
ion coefficient as a function of the photon energy differs from that o
bserved previously at lower temperature.