Electrical Properties of Organic–Inorganic Semiconductor Device Based on Rhodamine-101

Abstract

Rhodamine-101 (Rh101) thin films on n-type Si substrates have been formed by means of evaporation, thus Sn/Rh101/n-Si heterojunctions have been fabricated. The Sn/Rh101/n-Si devices are rectifying. The optical energy gaps have been determined from the absorption spectra in the wavelength range of 400 nm to 700 nm. Rh101 has been characterized by direct optical absorption with an optical edge at 2.05 ± 0.05 eV and by indirect optical absorption with an optical edge at 1.80 ± 0.05 eV. It was demonstrated that trap-chargelimited current is the dominant transport mechanism at large forward bias. A mobility value of l = 7.31 9 10 À6 cm 2 V À1 s À1 for Rh101 has been obtained from the forward-bias current-voltage characteristics.

Electrical characterization of DC sputtered ZnO/p-Si heterojunction

“…where ˛ is the absorption coefficient, B is a constant and h is the plank constant. The exponent m depends on the nature of the transition, m = 1/2, 2, 3/2, or 3 for allowed direct, allowed nondirect, forbidden direct, or forbidden nondirect transitions, respectively [22,23]. It is well known that ZnO has an allowed direct band gap and m = 1/2 was used for the band gap calculation.…”