Band Offsets and Photoluminescence Thermal Quenching in Mid-Infrared Emitting GaInAsSb Quantum Wells with Quinary AlGaInAsSb Barriers
Band Offsets and Photoluminescence Thermal Quenching in Mid-Infrared Emitting GaInAsSb Quantum Wells with Quinary AlGaInAsSb Barriers
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DOI：
10.1143/jjap.49.031202
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发表时间：
2010-03
影响因子：
1.5
通讯作者：
G. Sȩk;M. Motyka;K. Ryczko;F. Janiak;J. Misiewicz;S. Belahsene;G. Boissier;Y. Rouillard
中科院分区：
文献类型：
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作者：
G. Sȩk;M. Motyka;K. Ryczko;F. Janiak;J. Misiewicz;S. Belahsene;G. Boissier;Y. Rouillard
用光反射谱研究了GaSb衬底上分子束外延生长的Ga_（0.35）In_（0.65）As_（0.32）Sb_（0.68）/Al_（0.25）Ga_（0.50）In_（0.25）As_（0.24）Sb_（0.76）量子威尔斯的光跃迁。根据与能级计算的比较，化学导带偏移率已被确定为78%。这转化为真实的结构中的65%（即，在应变包含之后），这是当与类似的但具有四元势垒的量子威尔斯相比时，在五元势垒系统中有利于价带中增强的限制的预期带偏移比修改的证据。这使我们能够解释主要的光致发光热猝灭机制，并连接载流子激活能与激子在低温下的离域和空穴在室温下通过受限态阶梯的逃逸。
Optical transitions in Ga0.35In0.65As0.32Sb0.68/Al0.25Ga0.50In0.25As0.24Sb0.76 quantum wells grown by molecular beam epitaxy on GaSb substrates have been detected by photoreflectance. Based on comparison with energy level calculations, the chemical conduction band offset ratio has been determined to be 78%. This translates into 65% in the real structure (i.e., after strain inclusion) which is an evidence of the expected band offset ratio modification in a quinary barrier system in favor of enhanced confinement in the valence band, when compared to similar quantum wells but with quaternary barriers. This has allowed us to explain the main photoluminescence thermal quenching mechanisms and connect the carrier activation energies with delocalization of excitons at low temperatures and the escape of holes via the confined states ladder at room temperature.