Growth and optical properties of GaSb/GaAs type-II quantum dots with and without wetting layer
Growth and optical properties of GaSb/GaAs type-II quantum dots with and without wetting layer
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DOI：
10.7567/jjap.54.04dh01
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发表时间：
2015-01
影响因子：
1.5
通讯作者：
T. Kawazu;Takeshi Noda;T. Mano;Y. Sakuma;H. Sakaki
中科院分区：
文献类型：
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作者：
T. Kawazu;Takeshi Noda;T. Mano;Y. Sakuma;H. Sakaki
我们研究了润湿层（WL）对GaAs中GaSb II型量子点（QD）光学性质的影响。通过液滴外延生长GaSb量子点，其中Ga液滴首先在GaAs上形成，然后暴露于Sb通量，随后进行退火步骤。通过调节退火温度，我们制备了具有和不具有良好定义的WL状结构的GaSb量子点。光致发光（PL）的测量结果表明，高温退火的样品表现出较强的PL的WL，而WL发光是相当弱的样品在低温下退火。随着测量温度T的增加，没有WL的GaSb量子点的PL能量降低。相反，具有WL的GaSb量子点的PL能量几乎不依赖于T。这些PL的能量转移解释考虑的空穴人口和能量依赖的吸收的影响。
We investigated the effect of a wetting layer (WL) on the optical properties of GaSb type-II quantum dots (QDs) in GaAs. GaSb QDs were grown by droplet epitaxy, where Ga droplets are first formed on GaAs and then exposed to Sb flux, followed by an annealing step. By adjusting the annealing temperature, we fabricated GaSb QDs with and without a well-defined WL-like structure. Photoluminescence (PL) measurements showed that the high-temperature-annealed samples exhibit a strong PL of the WL, whereas the WL luminescence is quite weak for the samples annealed at low temperatures. As the measurement temperature T increases, the PL energy decreases for the GaSb QDs without the WL. In contrast, the PL energy of the GaSb QDs with the WL has little dependence on T. These PL energy shifts are explained by considering the effects of the hole population and energy-dependent absorption.