Determination of the Np and pP heterojunction quality in Al_xGa_1-xAs LPE-grown double heterostructures from the capacitance measurements

Abstract

it is demonstrated that among commercial AI,Ga, _,As lasers there are three types of double heterostructure which differ in their capacitance (C) versus voltage (v) behaviour at 77 K. This is explained by t h e difference in extent of their anisotype heterointerface. It is also shown that t h e following properties of these double heterostructures can be determined: (1) pP heterojunction quality (determined from C(v) profiling data (N(W dependences) at 300 K) and Np heterojunction quality (determined from C(V) dependences at 77 K ) ; (2) the position of t h e pn junction, t h e magnitude of its displacement (if there is any) from the anisotype heterojunction and the layer of the structure in which it is displaced (determined from the spectral photocurrent response measurements at 300 and 77 K). Ail t h e mentioned techniques are non-destructive.