Light Sensitive Properties and Temperature-Dependent Electrical Performance of n-TiO2/p-Si Anisotype Heterojunction Electrochemically Formed TiO2 on p-Si

• Published in: Journal of electronic materials 2021-09, Vol.50 (9), p.5184-5195
• Main Authors: Koca, M., Yilmaz, M., Ekinci, D., Aydoğan, Ş.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electric potential; Electrodes; Electronics and Microelectronics; Emission analysis; Heterojunction devices; Instrumentation; Interfaces; Light; Materials Science; Metal oxides; Morphology; Optical and Electronic Materials; Optical properties; Original Research Article; Oxide coatings; Photodiodes; Science education; Silicon substrates; Silicon wafers; Solid State Physics; Structural analysis; Temperature dependence; Thermionic emission; Thin films; Titanium dioxide; Voltage
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-021-09040-1

We report the fabrication, electrical characteristics and light sensitivity of n -TiO 2 / p -Si heterojunction devices in which the TiO 2 layer was grown on p -Si substrates by cathodic electrodeposition. After the structural, morphological, and optical characterization of the deposited metal oxide film, 15 devices were fabricated. One was analyzed by current–voltage ( I–V ) and capacitance–voltage ( C–V ) analyses in a wide temperature range. Furthermore, another device was exposed to light and the I – V measurements were analyzed to investigate the light response of the n -TiO 2 / p -Si heterojunction. The device exhibited a photodiode property such that the reverse bias current value of the heterojunction significantly increased with exposure to the light. Temperature-dependent I–V and C–V measurements of the device showed that the device characteristics depend on both temperature and voltage. Thermionic emission and Norde method were used to evaluate temperature-related I–V measurements. According to the experimental results, it was observed that the barrier height increased [ranging from 0.24 eV (80 K) to 0.76 eV (300 K)] with increasing temperature and the ideality factor decreased [ranging from 4.94 (80 K) to 3.17 (300 K)]. This behaviour was attributed to the inhomogeneous barrier height of the n -TiO 2 / p -Si.