研究了热退火对飞秒激光脉冲在空气中微构造的黑硅材料的光致发光(PL)时间分辨光谱和发光强度衰减性质的影响，分析了退火后黑硅材料内光生载流子的运动和缺陷的性质。通过应用双指数函数拟合PL的强度衰减曲线，得到退火导致黑硅材料光谱变化的可能机理。采用热扩散理论说明退火造成氧缺陷的增加和非平衡载流子辐射复合率的增大，导致退火黑硅的PL强度随着退火温度的升高而增大。退火后时间常数增大且慢衰减过程比重增大，说明退火消除并修复了微构造表面及内部的一些缺陷，增加表面束缚态，减小非辐射复合中心的密度，从而增大了辐射复合所占的比重，导致退火黑硅的PL谱强度增大。黑硅发光的最佳退火条件是800 ℃真空退火30 min。

Effect of annealing on the properties of time-resolved spectra of photoluminescence (PL) and the decay in PL intensity of black silicon processed by femtosecond laser pulses in air is studied. The motion of photon-generated carriers and the property of defects in black silicon after annealing have been analyzed. By fitting the PL decay profile with double exponential function, the probable mechanism of spectral change of black silicon due to annealing is given. The increase in PL intensity of black silicon after annealing is the result of the increased oxygen defects resulting from the radiative recombination rate of nonequilibrium carriers. A theory of thermal diffusion is put forward to explain the observation that the PL intensity of black silicon increases with the annealing temperature. The increasing time constants and the ratio of the slow decay process are attributed to the fact that some defects on the microstructured surface and within silicon material have been eliminated and restored by annealing that leads to the increasing of the surface bound state, thus reducing the density of nonradiative recombination centers. The ratio of radiative recombination increases, resulting in the increase in PL intensity of annealed black silicon. The best annealing condition for the PL of black silicon found is annealing at 800 ℃ for 30 min in vacuum.