Annealing study of carrier concentration in gradient-doped GaAs/GaAlAs epilayers grown by molecular beam epitaxy.
Annealing study of carrier concentration in gradient-doped GaAs/GaAlAs epilayers grown by molecular beam epitaxy.
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DOI：
10.1364/ao.48.001715
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发表时间：
2009-03
期刊：
影响因子：
1.9
通讯作者：
Yijun Zhang;Benkang Chang;Zhi Yang;Jun Niu;Y. Xiong;F. Shi;Hui Guo;Yiping Zeng
中科院分区：
文献类型：
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作者：
Yijun Zhang;Benkang Chang;Zhi Yang;Jun Niu;Y. Xiong;F. Shi;Hui Guo;Yiping Zeng
我们利用电化学电容电压分布测量了分子束外延生长的梯度掺杂GaAs/GaAlAs外延层在600℃退火前后的载流子浓度分布，以研究退火过程中透射模式GaAs光电阴极的内部变化。结果表明，退火后载流子浓度有所增加。结果，梯度掺杂GaAs发射层的总能带弯曲能量在退火后增加了25.24%，这改善了光生电子向表面的运动。另一方面，退火过程导致GaAs和GaAlAs之间的载流子浓度差异更大，这导致后界面势垒降低，从而减少了高能光电子的数量。
We measured the carrier concentration distribution of gradient-doped GaAs/GaAlAs epilayers grown by molecular beam epitaxy before and after annealing at 600 degrees C, using electrochemical capacitance voltage profiling, to investigate the internal variation of transmission-mode GaAs photocathodes arising from the annealing process. The results show that the carrier concentration increased after annealing. As a result, the total band-bending energy in the gradient-doped GaAs emission layer increased by 25.24% after annealing, which improves the photoexcited electron movement toward the surface. On the other hand, the annealing process resulted in a worse carrier concentration discrepancy between the GaAs and the GaAlAs, which causes a lower back interface potential barrier, decreasing the amount of high-energy photoelectrons.