Electrically pumped ultraviolet lasing from ZnO in metal-insulator-semi devices
Electrically pumped ultraviolet lasing from ZnO in metal-insulator-semi devices
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DOI：
10.1007/s00339-013-7710-7
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
K. Wu;P. Ding;Yang-Ming Lu;Xinhua Pan;Haiping He;Jingyun Huang;Binghui Zhao;Cong Chen;
中科院分区：
文献类型：
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作者：
K. Wu;P. Ding;Yang-Ming Lu;Xinhua Pan;Haiping He;Jingyun Huang;Binghui Zhao;Cong Chen;
在室温下实现了电泵浦ZnO薄膜金属-绝缘体-半导体（MIS）二极管的紫外随机激光输出。采用等离子体辅助分子束外延生长了ZnO薄膜。通过电子束蒸发沉积两种不同类型的绝缘体层，SiOx（0<x≤2）和AlOx（0<x≤1.5）。X射线衍射实验发现这些氧化物层是无定形的（或微晶的），并且X射线光电子能谱证实Si和Al被完全氧化。与使用SiOx作为绝缘层的器件相比，具有蒸发AlOx层的二极管显示出更低的工作阈值正向电流（0.20 mA至0.26 mA）和更高的发射强度。通过对电致发光光谱的功率傅里叶变换，推导出了表明形成闭环路径的周期性特征。两种器件的腔长均随正向电流的增大而增大，而在相同的工作电流下，掺AlOx的器件总是获得较大的腔长。性能的改善归因于AlOx层中更大的空穴量。这些结果表明，蒸发的AlOx可以作为异质结构的良好的电子阻挡层和空穴供应层。
Electrically pumped ultraviolet random lasing was achieved in metal-insulator-semiconductor (MIS) diodes based on ZnO films at room temperature. The ZnO films were grown by plasma assisted molecular beam epitaxy. Two different kinds of insulator layers, SiOx(0<x≤2) and AlOx(0<x≤1.5) were deposited by electron beam evaporation. X-ray diffraction experiments found these oxide layers were amorphous (or microcrystals), and X-ray photoelectron spectroscopy confirmed the Si and Al were fully oxidized. Compared with devices using SiOxas the insulator layer, diodes with evaporated AlOxlayers showed a lower working threshold forward current (∼20 mA to ∼26 mA) and higher emission intensity. Periodic features indicating formation of closed-loop paths were deduced by the power Fourier transform of electroluminescence spectra. The cavity length of both devices increased as forward currents increased, while a larger cavity length was always obtained in the AlOx-involved device under the same working current. The improved performance was attributed to larger hole amount in AlOxlayers. These results revealed that evaporated AlOxcan serve as good electron blocking and hole supplying layers for hetero-structures.