Title Investigation of carrier dynamics in InN, InGaN, and GaAsBi by optical pump-probe techniques /
Translation of Title Nepusiausvirųjų krūvininkų dinamikos tyrimas sužadinimo-zondavimo metodikomis InN, InGaN, GaAsBi.
Authors Nargelas, Saulius
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Pages 38
Keywords [eng] Nitride semiconductors ; GaAsBi ; carrier dynamics ; transient gratings ; differential transmission
Abstract [eng] The thesis is dedicated to investigation of carrier dynamics in InN, InGaN, and GaAsBi heterostructures by using light-induced transient gratings and differential transmission techniques. The experimental studies in a wide range of excess carrier densities and temperatures revealed that trap-assisted Auger recombination is the dominant recombination mechanism in MBE-grown InN layers at room temperature. Investigation of carrier dynamics in In-rich InGaN alloys revealed that density of fast nonradiative recombination centers increases with Ga content. The correlation between excess carrier lifetime and diffusion coefficient in MOCVD-grown single InGaN layer with 13% In is governed by diffusive flow to the extended defects. Investigations of carrier lifetime and diffusivity dependence on excitation fluence indicated that both nonradiative and radiative recombination contribute to an increase of excess carrier recombination rate at high photo-excitation levels in MOCVD-grown InGaN multiple quantum wells. Transient grating measurements in MBE-grown GaAsBi layers with different Bi content revealed that Bi induced potential fluctuations determine the tenfold decrease in nonequilibrium hole mobility, if compare to GaAs.
Type Summaries of doctoral thesis
Language English
Publication date 2013