Characterization of AlGaN-based metal-semiconductor solar-blind UV photodiodes with IrO₂ Schottky contacts

详细信息	查看全文 | 推荐本文 |

• 作者：L. van Schalkwyk ; ^{Louwrens.VanSchalkwyk@up.ac.za} ; W.E. Meyer ; F.D. Auret ; J.M. Nel ; P.N.M. Ngoepe ; M. Diale
• 关键词：AlGaN ; Solar-blind ; Ultraviolet ; Iridium oxide ; Schottky ; Photodiode ; Optoelectronic
• 刊名：Physica B
• 出版年：2012
• 期刊代码：53_09214526
• 类别：ph
• 出版时间：15 May, 2012
• 卷：407
• 期：10
• 页码：1529-1532
• 文件大小：333 K

摘要

Intrinsically solar-blind ultraviolet (UV) AlGaN-based Schottky photodiodes were fabricated using Iridium oxide (IrO₂) as the Schottky barrier material. The Ir Schottky contacts were annealed at 700 掳C under O₂ ambient and the photodiodes characterized with an optoelectronic system. The main parameters extracted from I-V measurements were an average ideality factor of 1.38, a Schottky barrier height of 1.52 eV, a reverse leakage current density at 鈭? V bias of 5.2 nA/cm² and series resistance of . After spectral characterization, it was found that annealing, alone, of the Ir contact to form the more UV transmissive IrO₂ does not always improve the responsivity. The deposition of a Au probe contact on the IrO₂ contact increased the responsivity from 40 mA/W to 52 mA/W at 275 nm with respect to the annealed Ir contact. However, the ideality factor degraded to 1.57, Schottky barrier height lowered to 1.19 eV, reverse leakage current density increased to 49 nA/cm² and series resistance decreased to with the addition of the Au contact. The radiation hardness of AlGaN was also confirmed after studying the effects of 5.4 MeV He-ion irradiation using ²⁴¹Am for a total fluence of  cm^鈭?.