We report on the anomalous excitation-power dependence of the band-edge emission in Si after 2 MeV electron irradiation. It is well-established that the dependence of the emission intensity I on the excitation power L is generally follows the power law, I ∝ L n with the exponent n between 1 and 2. However, the exponent n increases after the electron irradiation and becomes larger than 2 at temperatures from 60 to 150 K in all the measured samples. The present dependence can be explained by a simple model: the radiation-induced defects act as dominant recombination centers in the low excitation-power range, but their activity becomes saturated in the high excitation-power range.

中文翻译：

---

含辐射致缺陷的硅中带边发射的反常激发功率依赖性

我们报告了2 MeV电子辐照后Si中带边发射的异常激发功率依赖性。公认的是，发射强度I对激发功率L的依赖性通常遵循幂定律I ∝ L n，指数n在1和2之间。但是，指数n在电子辐照后会增加并变为在所有被测样品中，从60到150 K的温度都大于2。当前的依赖性可以用一个简单的模型来解释：辐射引起的缺陷在低激发功率范围内起着主要的复合中心的作用，但在高激发功率范围内它们的活性就饱和了。