Fabrication and electrical characterization of thermally deposited amorphous Se0.82In0.18 on n-Si (100)

Abstract

Amorphous (a-) Se 0.82 In 0.18 thin films have been deposited onto n-type silicon (n-Si) single crystal, using the three-temperature technique, in the fabricated configuration of Au/a-Se 0.82 In 0.18 /n-Si/Al. The current densityvoltage (J -V ) characteristics have been measured at different isotherms in the range of 198-313 K, thus inspecting the conduction mechanisms comparing with Au/a-Se/nSi/Al heterojunctions. The analysis proved that the forward bias is characterized by two parts: current increasing exponentially with the applied voltage (low voltage bias region, V < 0.2 V), and non-exponentially in the higher voltage region (V > 0.2 V). At the low bias region, the current was dominated by a multi-tunneling capture-emission process with a rather temperature-independent effect in the temperature range investigated. However, at the high voltage region, the effect of temperature becomes more pronounced with an ohmic character in the range of 198 to 273 K. For temperatures higher than 273 K, and below the glass transition temperature of a-Se 0.82 In 0.18 (T g ∼ 330 K), the high voltage region could be subdivided into two parts: an ohmic conduction range that limited at bias voltage of 0.20 V < V < 0.46 V, and a space charge limited current region for bias voltage of V > 0.46 V. The reverse J -V characteristics showed a deviation from that of the ideal diode behavior, analogous to that of pure a-Se/n-Si heterojunctions.