Persistent photoconductivity has been observed at low temperatures in thin, unintentionally doped GaInP/GaAs/GaInP quantum wells. The two-dimensional electron gas was studied by low field Hall and Shubnikov-de Haas effects. After illumination with red light, the electron concentration increased from low 1011 cm-2 to more than 7×1011 cm-2 resulting in an enhancement of both the carrier mobility and the quantum lifetime. The persistent photocarriers cannot be produced by DX-like defects since the shallow dopant concentration in the GaInP layers is too low to produce the observed concentration. We suggest that the persistent carriers are produced by photoionization of deep intrinsic donors in the GaInP barrier layer. We also report observation of a parallel conduction path in GaInP induced by extended illumination.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)