Spectral Response of p‐n Heterojunctions

Semiconductor heterojunctions have been grown by the deposition of III‐V solid solutions on GaAs substrates and their optical properties studied in detail. While the general picture is that deduced from simple theory, some interesting second order phenomena have been observed. Effects considered include absorption in the wide gap material, loss of photocurrent due to the conduction band spike and notch and high field absorption effects in the narrow gap material transition region. Experimental results are presented and the incidence of these effects in real heterojunctions discussed.