Photoluminescence dynamics of exciton-exciton scattering in a lightly alloyed InGaN thin film
Photoluminescence dynamics of exciton-exciton scattering in a lightly alloyed InGaN thin film
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DOI：
10.1063/1.3054166
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发表时间：
2008-12
影响因子：
4
通讯作者：
M. Nakayama;K. Sakaguchi
中科院分区：
文献类型：
--
作者：
M. Nakayama;K. Sakaguchi
我们研究了轻合金化In0.02Ga0.98N薄膜在10K强激发条件下的光致发光(PL)动力学。在In0.02Ga0.98N薄膜中，激子-激子散射引起的光致发光(PL)带，即所谓的P带，在高于∼3μJ/cm~2的激发功率区出现了阈值性质。在激子-激子散射发生的条件下，光致发光衰变分布由P带的快衰变分量(约10ps量级)和局域激子带的慢衰变分量组成。随着激励功率的增大，P波段的衰减时间逐渐缩短。衰变时间的变化可以用P发射的终态--下极化子分支的类光子特性来定性地解释。此外，我们还清楚地观察到了P带峰值能量的时间变化，它反映了激子系统的有效温度。P带的能量漂移表明，P发射在不同温度下都有不同程度的变化。
We have investigated the photoluminescence (PL) dynamics of a lightly alloyed In0.02Ga0.98N thin film under intense excitation conditions at 10 K. In the In0.02Ga0.98N thin film, a PL band due to exciton-exciton scattering, the so-called P band, appears with a thresholdlike nature in the excitation-power region higher than ∼3 μJ/cm2. Under the condition that the exciton-exciton scattering occurs, the PL-decay profile consists of a fast decay component of the P band (of the order of 10 ps) and a slow decay component of a localized exciton band. The decay time of the P band gradually shortens with increasing excitation power. The change in the decay time can be explained qualitatively by the photon-like characteristics of the lower polariton branch that is the final state of the P emission. Furthermore, we have clearly observed the temporal change in the peak energy of the P band, which reflects an effective temperature of the excitonic system. The energy shift of the P band suggests that the P emission pro...