Performance Comparisons of Light‐Emitting Thyristors with and without Indium Tin Oxide Transparent Conductive Layers

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2018-04, Vol.215 (8), p.n/a
• Main Authors: Chen, Ching‐Ho, Tseng, Ming‐Chun, Chen, Yu‐Jie, Wuu, Dong‐Sing, Horng, Ray‐Hua
• Format: Article
• Language: English
• Subjects: Current voltage characteristics; Electrodes; indium tin oxide; Indium tin oxides; Light; light‐emitting thyristors; Luminous intensity; Performance assessment; Thermal stability; Thin films; Thyristors; Tin oxides
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201700442

Indium tin oxide (ITO) deposited on different contact layers are studied to be used as transparent electrodes on light‐emitting thyristors (LETs). The performance of LETs with either ITO or a metal electrode is compared. It is found that the ITO could be used as an ohmic contact layer, because the ITO layer was deposited on the contact layer with heavy dopant concentration. Moreover, the thermal annealing at 400 °C is necessary. The S‐shaped current–voltage characteristic of LETs with either metal or ITO electrodes is compared. The LETs with an ITO thin film exhibit excellent performance. The light output power and thermal stability of the LETs with the ITO layer are higher than those of the LETs with the metal electrode. The light‐extraction efficiency of the ITO‐LET is 24% higher than that of the metal‐LET. The surface temperature of the ITO‐LET is 9.57 °C lower than that of the metal‐LET. The ITO electrode on the LET chip significantly improved the light intensity distribution properties as compared with the metal electrode on the LET chip. The above results are promising for the development of ITO thin films to enhance the performance of LET applications. In this study, an ITO thin film is deposited onto LETs with n+‐GaAs contact layers to construct three terminal LET devices (shown in Fig. (b)). The electrical and optical properties of LETs with the ITO thin films used as current‐spreading layers to enhance the light‐extraction efficiency are compared with those of LETs with AuGe/Au electrodes and described in detail.