MOVPE growth mechanisms of dilute bismide III/V alloys

Abstract

This paper summarizes the present understanding of the growth of Ga(AsBi) on GaAs substrates using metal organic vapor phase epitaxy (MOVPE). A growth model including Bi segregation is developed and the influence of several growth parameters, such as the applied growth temperature, the growth rate and the partial pressures of the precursors, are investigated in detail. Also, effects, beyond pure source decomposition, of the low growth temperature needed for the deposition of the highly metastable material system are summarized. Optimizing the growth conditions enables the deposition of Ga(AsBi) layers with more than 7% Bi that show strong room temperature photoluminescence without the necessity of annealing. Bi acts as a surfactant during the growth that reduces the defect density and unintentional carbon doping of the crystals. Besides using the established Bi precursor trimethylbismuth (TMBi), the growth of Ga(AsBi) with alternative Bi precursors tritertiarybutylbismuth (TTBBi) and triisopropylbismuth (TIPBi) is discussed. Furthermore, first results on Ga(AsBi) containing an electrically pumped single quantum well laser grown with MOVPE are presented. These devices might enable high efficiency infrared laser devices in future.