Electrical conduction mechanism in amorphous thin films of the system Pb xGe 42− xSe 58

Abstract

Bulk glasses of composition Pb x Ge 42− x Se 58 ( x = 7, 8 and 9) were prepared by melt quench technique. The thermal behaviour of the glass system was investigated by differential scanning calorimetry. The double stage crystallization was observed in these glasses. Amorphous thin films of Pb x Ge 42− x Se 58 ( x = 7, 8 and 9) were prepared by thermal evaporation of bulk glasses of the same composition on the glass substrates. Electrical conduction mechanism in Pb x Ge 42− x Se 58 thin films in the temperature range of 300–425 K with both symmetric and asymmetric electrodes is reported. The results were interpreted in terms of a Poole–Frenkel type of conduction mechanism over the entire range of temperatures and field strengths. Tunnel characteristics are reported in ultra thin films and the metal semiconductor interface barrier heights are determined.