Fabrication and characterization of high performance MSM UV photodetector based on NiO film

In this study, metal-semiconductor-metal (MSM) ultraviolet photodetector based on NiO film was fabricated on n-type Si (100) substrate. The NiO film was deposited on Si (100) by using RF magnetron sputtering of NiO target at 100 °C. The film showed cubic bunsenite structure with (200) preferred orientation as confirmed through XRD analysis. The band gap of NiO film was evaluated from UV-vis reflectance specroscopy and it was found to be 3.38 eV. To study the photodetection performance of NiO film, Au metal contacts were deposited on the film through RF sputtering system. The photodetection characteristics of the photodetector such as spectral response, photosensivity, internal gain, rise and fall time were investigated. The Au/NiO/Au MSM UV device displayed maximum value of responsivity (4.5 A/W) upon exposure to 365 nm UV light at 5 V bias. The photosensivity was calculated to be 6.4 × 103% whereas the internal gain of the photodetector was estimated to be 6.5 × 101. In addition, the rising and falling time were found to be 266 ms and 200 ms, respectively. The fabricated device exhibited excellent stability and repeatability in its performance.