Optical gain observation on silicon nanocrystals embedded in silicon nitride under femtosecond pumping
Optical gain observation on silicon nanocrystals embedded in silicon nitride under femtosecond pumping
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DOI：
10.1063/1.3607276
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发表时间：
2011-07
影响因子：
4
通讯作者：
B. Monroy;O. Crégut;M. Gallart;B. Hönerlage;P. Gilliot
中科院分区：
文献类型：
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作者：
B. Monroy;O. Crégut;M. Gallart;B. Hönerlage;P. Gilliot
我们报告了通过可变条带长度技术测量的嵌入氮化硅中的硅纳米晶体（Si-nc）的正光学增益的观察结果。我们证明了受激发射的开始，并报告在最高激发功率（6.5 W/cm2）下增益系数高达 52 cm−1。光致发光动力学在纳秒和微秒范围内呈现出两种不同的复合寿命。这可以通过 Si-nc 表面氮诱导局域态中的快速载流子捕获和随后的缓慢辐射复合来解释，表明辐射表面态中的载流子捕获在 Si-nc 的光学增益机制中起着至关重要的作用。
We report the observation of positive optical gain in silicon nanocrystals (Si-nc) embedded in silicon nitride measured by the variable stripe length technique. We evidence the onset of stimulated emission and report gain coefficients up to 52 cm−1 at the highest excitation power (6.5 W/cm2). Photoluminescence dynamics presents two distinct recombination lifetimes in the nanosecond and the microsecond ranges. This was interpreted in terms of fast carrier trapping in nitrogen-induced localized states in the Si-nc surface and subsequent slow radiative recombination, suggesting that carrier trapping in radiative surface states plays a crucial role in the optical gain mechanism of Si-nc.