Photo-electrical Characterization of New CuAlNi/n-Si/Al Schottky Photodiode Fabricated by Coating Thin-Film Smart Material

Authors : Oktay KARADUMAN, Canan AKSU CANBAY

Pages : 329-341

Doi:10.55525/tjst.1108761

View : 12 | Download : 5

Publication Date : 2022-09-30

Article Type : Research Paper

Abstract :Micro/nano scale thin-film shape memory alloys insert ignore into journalissuearticles values(SMAs); have been used in many different miniaturized systems. Using them as thin-film metal components in fabrication of Schottky photodiodes has started a few years ago. In this work, a new SMA-photodiode device with CuAlNi/n-Si/Al structure was produced by coating nano-thick CuAlNi SMA film onto n-Si wafer substrate via thermal evaporation. The photoelectrical I-V, C-V and I-t photodiode signalization tests were performed under dark and varied artifical light power intensities in room conditions. It was observed that the new device exhibited photoconductive, photovoltaic and capacitive behaviors. By using conventional I-V method, the diode parameters such as electrical ideality factor insert ignore into journalissuearticles values(n);, Schottky barrier height insert ignore into journalissuearticles values(ϕb); and rectification ratio insert ignore into journalissuearticles values(RR); of the produced photodevice for the condition of dark environment were computed as 12.5, 0.599 eV and 1266, respectively. As good figure of merits, the photodiode’s performance parameters of responsivity insert ignore into journalissuearticles values(Rph);, photosensivity insert ignore into journalissuearticles values(%PS); and spesific detectivity insert ignore into journalissuearticles values(D*); maxima values determined for at -5 V reverse voltage bias and under 100 mW/cm2 of light power intensity condition are as 0.030 A/W insert ignore into journalissuearticles values(or 30 mA/W);, 18693 and 1.33×1010 Jones, respectively. The current conduction mechanism analysis revealed that the space charge limited conduction insert ignore into journalissuearticles values(SCLC); mechanism is the dominant current conduction mechanism. By the drawn reverse squared C-2-V plots, the values of diffusion potential insert ignore into journalissuearticles values(Vd);, donor concentration insert ignore into journalissuearticles values(ND);, Fermi level insert ignore into journalissuearticles values(EF); and also barrier height insert ignore into journalissuearticles values(ϕb); were determined for the SMA-photodiode. The results indicated that the new SMA-photodiode device can be useful in optoelectronic communication systems and photosensing applications.
Keywords : Schottky photodiode, thin film shape memory alloy, space charge limited current, photosensitivity, detectivity