刻划的富硅二氧化硅/p-Si结构的光致发光和电致发光

Photoluminescence and Electroluminescence from Scored Si-Rich SiO_2 Film/p-Si Structure

以磁控溅射方法于 p- Si上淀积富硅二氧化硅 ,形成富硅二氧化硅 /p- Si结构 ,用金刚刀在其正面刻划出方形网格后在 N2 气氛中退火 ,其光致发光 (PL)谱与未刻划的经同样条件退火的对比样品的 PL 谱有很大不同 .未刻划样品的 PL 谱只有一个峰 ,位于 840 nm (1.48e V) ,而刻划样品的 PL 谱是双峰结构 ,峰位分别位于 6 30 nm(1.97e V)和 840 nm.80 0℃退火的刻划富硅二氧化硅 /p- Si样品在背面蒸铝制成欧姆接触和正面蒸上半透明金电极后在正向偏压 10 V下的电致发光 (EL)强度约为同样制备的未经刻划样品在同样测试条件下的 EL 强度的 6倍 .EL 谱形状也有明显不同 ,表现在 :未经刻划样品的 EL 谱可以分解为两个高斯峰 ,峰位分别位于 1.83e V和2 .2 3e V;而在刻划样品 EL 谱中 1.83e V发光峰大幅度增强 ,还产生了一个新的能量为 3.0 e V的发光峰 .认为刻划造成的高密度缺陷区为氧化硅提供了新的发光中心并对其中某些杂质起了吸除作用 ,导致 PL 和 EL 光谱改变 .

The Si-rich SiO_2/p-Si structure has been fabricated with two-target alternative magnetron sputtering technique.After the Si-rich SiO_2/p-Si sample having been scored by diamond tip on the front surface and annealed at 800℃ in N_2 the photoluminescence(PL) spectrum is found quite different from that from the unscored one,which having been annealed in the same condition.The latter has only one PL band peaking at about 148eV,while the former is a double-band PL spectrum with peaks at both 148eV and 197eV.The electroluminescence(EL)form the Au/scored Si-rich SiO_2 film/p-Si sample is about 6 times in intensity of that of the Au/unscored one.The EL spectrum of the unscored sample can be decompounded into two Gaussian luminescence bands with peaks at about 183eV and 223eV,while in that of the scored one,the intensity of the 183eV peak is enhanced significantly,and a new Gaussian band with peak at about 30eV appears.It is believed that the high defect-density region produced by the score provides the SiO_2 layer with new luminescence centers and getters some impurities in it,as results in the change in EL and PL spectra.