Investigation of deep level defects in n-type GaAsBi
Investigation of deep level defects in n-type GaAsBi
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DOI：
10.1117/12.2607597
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发表时间：
2022-03
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通讯作者：
M. Fregolent;M. Buffolo;C. de Santi;Sho Hasegawa;Junta Matsumura;H. Nishinaka;M. Yoshimoto;G. Meneghesso;E. Zanoni;M. Meneghini
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作者：
M. Fregolent;M. Buffolo;C. de Santi;Sho Hasegawa;Junta Matsumura;H. Nishinaka;M. Yoshimoto;G. Meneghesso;E. Zanoni;M. Meneghini
稀二酰亚胺是一类很有前途的半导体，由于其带隙的稳定性、物理性质的低温度依赖性和低俄歇复合系数，其在中红外光电器件，特别是激光器、光电探测器和异质结太阳能电池中找到应用。本文研究了低温分子束外延（MBE）生长的n型GaAs_（1-x）Bix（x = 1.2%）肖特基势垒二极管中的缺陷和深能级。通过电容深能级瞬态谱（C-DLTS）获得的原始结果表明：（a）在探测区域中只能检测到浓度低于1014 cm-3的四个多数载流子陷阱和两个少数载流子陷阱;（b）缺陷的浓度具有弱的位置依赖性，从而表明MBE是控制缺陷形成的有效生长技术。B。主要的电子和空穴陷阱的载流子捕获动力学的分析表明，（c）它们分别与位错和点缺陷相关联，捕获势垒为0.48 eV。最后，通过比较检测到的缺陷的DLTS特征，我们证明了（d）只有深能级可能与铋的存在有关，而其他能级已经在纯GaAs中发现。
Dilute bismides are a promising class of semiconductors that find applications in mid-infrared optoelectronic devices, especially lasers, photodetectors, and heterojunction solar cells owing to the tenability of the bandgap, the low temperature dependence of their physical properties, and the low Auger recombination coefficient. In this paper we investigate on the defects and deep levels in n-type GaAs1-xBix (x = 1.2 %) Schottky barrier diodes grown by low-temperature molecular beam epitaxy (MBE). Original results obtained by means of capacitance deep level transient spectroscopy (C-DLTS) indicate that: (a) only four majority and two minority carrier traps with concentration below 1014 cm-3 can be detected in the probed regions and (b) the concentration of the defects is weakly position-dependent, thus indicating that MBE is an effective growth technique to control defect formation. The analysis of the carrier capture kinetics of the dominant electron and hole traps show that (c) they are associated to a dislocation and a point defect with capture barrier of 0.48 eV, respectively. Finally, by comparing the DLTS signatures of the detected defects, we proved (d) that only a deep level is possibly associated to the presence of the bismuth, while the others were already found in pure GaAs.