FeSi2/Si junctions electricals characteristics

ABSTRACT In this work electrical and photovoltaic properties of FeSi2/Si junctions, which obtained in 3 different methods, are investigated. First of all Fe/n-Si and Fe/p-Si junctions are obtained on n-type and p-type silicon by e-beam evaporation at different substrate temparetures. It was seen, from the investigation of dark and illuminated current-voltage characteristics, that junctions have rectifying properties and photosensitivity. It is determinated that Fe/n-Si junctions which obtained at room temperature have the highest photovoltaics parameters ( Voc=210 mV, Jsc=33,6 uA/cm2). In other method FeSİ2 tablets, obtained by the stociometric powder mixture of iron and silicon, and P -FeSİ2 which synthesied in vacuum are evaporated by e-beam onto n-type and p- type Si substrates at T=Q.5°C and FeSİ2/Si heterojunctions are obtained. From the current- voltage measurements of these junctions, photovoltaic parameters of FeSİ2/n-Si heterojunctions are found as the highest (Voc=105 mV, Jsc=l,l uA/cm2 ). Crystalic structure, phase and electrical properties of the grown bulk samples are determined from the X-ray diffractions, DSC and resistivity measurements respectively. p-FeSi2 samples have orthorhombic structure and p-type conductivity. In last method, Fe(W)Si2/glass and Fe(W)Sİ2/n-Si heterojunctions are obtained by the evaporation of Fe(W)Sİ2 bulk polycrystalline on to glass and n-Si. p-Fe(W)Sİ2/n-Si junctions have the highest photovoltaic parameters (Voc=275 mV, Jsc=180 uA/cm2 and FF=0,23) of all heterojunctions. Fe(W)Sİ2 film on the glass has p-type conductivity and resistivity of film was p=2,7.10"3 Q-cm. Besides it was seen that p-Fe(W)Sİ2/n-Si heterojunction has photosensitivity in A.= 350- 1800 nm. Another important point for these heterojunctions is the high rectifying coefficient (Idirect/Ireverse=:1194), and the ratio of illuminated current to the dark current (i.e photosensitivity) under the reverse bias (Iiight/Idark =1790). Referring to these properties, p- Fe(W)Sİ2/n-Si heterojunctions can be used as photodiodes.Keywords: p-FeSİ2, Fe/Si junctions, FeSi2/Si heterojunctions, Electiric, Fotovoltaic