Influence of bismuth incorporation on the valence and conduction band edges of GaAs1−xBix

Abstract

We investigate the electronic properties of GaAs1−xBix by photoluminescence at variable temperature (T=10–430K) and high magnetic field (B=0–30T). In GaAs0.981Bi0.019, localized state contribution to PL is dominant up to 150K. At T=180K the diamagnetic shift of the free-exciton states reveals a sizable increase in the carrier effective mass with respect to GaAs. Such an increase cannot be accounted for by an enhanced localized character of the valence band states, solely. Instead, it suggests that also the Bloch states of the conduction band are heavily affected by the presence of bismuth atoms.

Recombination mechanisms and band alignment of GaAs1−xBix/GaAs light emitting diodes

“…On the other hand, type-II band alignment could potentially allow access to longer wavelengths. 10 The band alignment of the GaAsBi/GaAs interface remains uncertain with reports in the literature of type-I, 11,12 type-II, 13 and a nearly flat 14 conduction band offset. In this letter, we investigate the carrier recombination processes of GaAs 1Àx Bi x /GaAs LEDs to aid in the design and optimization of device structures.…”

“…In the temperature dependence, we measure the effects both in the CB and valence band (VB), where localization near the VB edge may play a key role for lower temperature dependence. 11 On the other hand, pressure mainly affects the CB, less influenced by Bi. There is no evidence of blue shift with increasing current injection (inset of Fig.…”

Impact of alloy disorder on the band structure of compressively strained GaBixAs1−x

“…III E, we consider the band edge alignment in compressively strained GaBi x As 1−x /GaAs samples. The band alignment at the GaBi x As 1−x /GaAs interface remains uncertain in the literature with reports suggesting that the conduction band offset is of type-I, 2,20,21 or type-II, 14 or nearly flat. 22 Our calculations support a type-I band alignment for all the samples considered.…”

Novel Dilute Bismide, Epitaxy, Physical Properties and Device Application

“…Measuring electron and hole effective masses provides a potential to unveil physics of hybridization of the Bi-related state with VB and CB. Pettinari et al [215] reported that the exciton mass of GaAs 0.981 Bi 0.019 was derived as 0.088m 0 from magnetic field dependent PL. They considered that both hole and electron effective masses increased and inferred that the localized potential of Bi atoms strongly affected both VB and CB.…”