The interplay of polarization fields and free carrier screening in In x Ga 1-x N/GaN (0.03 < x < 0.07) multiple quantum wells is studied by combining photoluminescence (time-integrated and time-resolved) and cathodoluminescence studies, in an excitation density range from 10 8 to 10 12 cm -2 of generated e-h pairs. For such low In content, the quantum-confined Stark effect is verified to rule the recombination dynamics, while effects of carrier localization in potential fluctuations have a minor role. Efficient field screening is demonstrated in CL steady-state high-injection conditions and in PL time-resolved experiments at the maximum excitation density. Under recovered nearly flat band conditions, quantum confinement effects are revealed and a high and possibly composition-dependent bowing parameter is extrapolated. Information on radiative and non-radiative rates for carrier recombination in the wells is obtained, both from steady-state and from time-resolved experiments, modelling the carrier dynamics in the framework of a theoretical rate equation model, which calculates electronic states and recombination rates in the nanostructure by coupling complete self-consistent solutions of Schrödinger and Poisson equations
POLARIZATION FIELD EFFECTS ON THE RECOMBINATION DYNAMICS IN LOW IN CONTENT INGAN MULTI-QUANTUM WELLS / N. ARMANI; F. ROSSI; C. FERRARI; L. LAZZARINI; A. VINATTIERI; M. COLOCCI; A. REALE; A. DI CARLO; V. GRILLO. - In: SUPERLATTICES AND MICROSTRUCTURES. - ISSN 0749-6036. - STAMPA. - 36:(2004), pp. 615-624. [10.1016/j.spmi.2004.09.019]
POLARIZATION FIELD EFFECTS ON THE RECOMBINATION DYNAMICS IN LOW IN CONTENT INGAN MULTI-QUANTUM WELLS
VINATTIERI, ANNA;COLOCCI, MARCELLO;
2004
Abstract
The interplay of polarization fields and free carrier screening in In x Ga 1-x N/GaN (0.03 < x < 0.07) multiple quantum wells is studied by combining photoluminescence (time-integrated and time-resolved) and cathodoluminescence studies, in an excitation density range from 10 8 to 10 12 cm -2 of generated e-h pairs. For such low In content, the quantum-confined Stark effect is verified to rule the recombination dynamics, while effects of carrier localization in potential fluctuations have a minor role. Efficient field screening is demonstrated in CL steady-state high-injection conditions and in PL time-resolved experiments at the maximum excitation density. Under recovered nearly flat band conditions, quantum confinement effects are revealed and a high and possibly composition-dependent bowing parameter is extrapolated. Information on radiative and non-radiative rates for carrier recombination in the wells is obtained, both from steady-state and from time-resolved experiments, modelling the carrier dynamics in the framework of a theoretical rate equation model, which calculates electronic states and recombination rates in the nanostructure by coupling complete self-consistent solutions of Schrödinger and Poisson equations
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