Experimental determination of the effective minority carrier lifetime in the operation of a quantum-well n-p-n heterojunction bipolar light-emitting transistor of varying base quantum-well design and doping

The authors show that the electrical characteristics of an n-p-n transistor structure can be used to determine experimentally, under dynamical operating conditions, the effective carrier lifetime of injected minority carriers in the quantum-well (QW) base region of a heterojunction bipolar light-emitting transistor. The carrier lifetime is progressively reduced from 134 ps (no base QW) to ∼35 ps by inserting single or double QWs of increasing width to enhance the effective capture cross section for injected carriers (electrons), and is further reduced to ∼10 ps by increasing the p-type doping from 5×10¹⁸ to 4×10¹⁹ cm^-3.