Intersubband Transitions of Normal Incidence N-Type Direct Band Gap Quantum Well Structures(invited)

摘要: Intersubband transitions using normal incidence in the conduction band of a direct gap semiconductor quantum well structure is very unconventional, yet useful infrared photodetectors (QWIPs). On other hand, absorption allowed both p-type QWIPs and indirect bandgap n-QWIPs. However, low electron effective mass high mobility Г valley made n-type more desirable for detection considering sensitivity speed. Normal without grating are especially attractive important large format focal plane array applications. In this paper, experimental results with InGaAs/AlGaAs GaAs/AlGaAs structures given which show obvious evidence intersubband transition under condition. The cause phenomenon can be either from sample processing testing conditions light has been directed to in-plane direction, or due intrinsic absorption. Three QWIP samples different device structures, procedures, examined study effects mesa edge, substrate metal-semiconductor interface diffusion. Theoretical models also understand mechanisms