Preparation and Performance Optimization of Boron-gallium Co-doped Zinc Oxide Transparent Electrodes

doi:10.15541/jim20250273

Abstract

Abstract:

Silicon carbide (SiC) photoconductive semiconductor switches (PCSS) are optoelectronic devices that utilize ultrafast pulsed lasers to modulate semiconductor resistivity for switching operations. Transparent oxide conductive films, especially zinc oxide thin films, are considered as a potential alternative electrode materials to reduce the on-resistance due to their excellent optical transparency and electrical conductivity. However, zinc oxide thin films are prone to ablation damage under high-energy pulsed laser irradiation, leading to crack formation and significantly affecting the device’s lifespan. Additionally, uneven local electric field distribution in the electrodes poses challenges to the long-term stability of the device. In this study, boron-gallium co-doped zinc oxide (BGZO) thin films were prepared by magnetron sputtering, and effects of annealing temperature (300-600 ℃) on their structural and electrical properties were investigated. X-ray diffraction and Hall effect measurements revealed that these films annealed at 400 ℃ exhibited optimal crystallinity and electrical performance, achieving a visible-light transmittance of 93% and a resistivity as low as 1.40×10^-2 Ω·cm. After integrating the optimized BGZO films as transparent electrodes into SiC PCSS devices, these BGZO-based devices, under 532 nm wavelength and 170 mJ pulsed laser excitation, exhibited more stable operation than conventional Ni-based electrodes, with reduced filamentary current damage at the SiC-electrode interface and improved electric field uniformity at the electrode edges. This study provides an optimized fabrication strategy for high-performance transparent conductive films and confirms their advantages in PCSS applications.

Key words: boron-gallium co-doped zinc oxide, transparent electrode, silicon carbide, photoconductive semiconductor switch

CLC Number:

TQ174

JIANG Shengnan, ZHENG Zhong, HE Weiyi, LIU Tao, PAN Xiuhong, CHEN Kun, GUO Hui, GAO Pan, LIU Chunjun, LIU Xuechao. Preparation and Performance Optimization of Boron-gallium Co-doped Zinc Oxide Transparent Electrodes[J]. Journal of Inorganic Materials, 2026, 41(4): 479-485.

Figures/Tables 12

Fig. 1 Diagrams of SiC PCSS electrode components (a) Au/TiW/Ni/SiC; (b) Au/TiW/BGZO/SiC

Fig. 2 XRD patterns of BGZO thin films before and after annealing at different temperatures

Fig. 3 EDS test results of BGZO thin films before and after annealing at different temperatures (a) As-dep.; (b) 300 ℃; (c) 400 ℃; (d) 500 ℃; (e) 600 ℃

Fig. 4 SEM images of BGZO thin films before and after annealing at different temperatures (a) As-dep.; (b) 300 ℃; (c) 400 ℃; (d) 500 ℃; (e) 600 ℃

Table 1 Zn/Ga ratio of BGZO thin films before and after annealing at different temperatures

Temperature/℃	Zn/Ga
As-dep.	43.65
300	43.38
400	33.90
500	34.54
600	32.82

Fig. 5 Transmittance of BGZO thin films before and after annealing at different temperatures

Fig. 6 Tauc plots of BGZO thin films before and after annealing at different temperatures

Table 2 Optical bandgap of BGZO thin films before and after annealing at different temperatures

Temperature/℃	Bandgap/eV
As-dep.	3.37
300	3.38
400	3.43
500	3.41
600	3.41

Table 3 Electrical properties of BGZO thin films at different annealing temperatures

Temperature/℃	Carrier concentration/ (×10²⁰, cm^-3)	Hall mobility/ (cm²·V^-1·s^-1)	Resistivity/ (Ω·cm)
300	0.278	0.62	0.362
400	1.382	1.78	0.028
500	1.834	2.64	0.014
600	0.783	5.06	0.016

Fig. 7 Output characteristics of PCSS

Fig. 8 SEM images of PCSS electrode edge (a) Ni-PCSS-1; (b) Ni-PCSS-2; (c) BGZO-PCSS-1; (d) BGZO-PCSS-2

Fig. 9 Electric field simulation of electrode edge (a) Electrode edge electric field simulation; (b) Distribution of electric field strength at the edge of simulated electrode

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