Carrier Transport in van der Waals Solid: 1,3-Diphenyl-5-(p-chlorophenyl)-2-pyrazoline in Single Crystalline State, Glassy State and in Supercooled Liquid State

Abstract

Abstract The hole drift mobilities in the title compound were measured in the single crystalline state (mp. 130°C), the glassy state (Tg, 16.5°C) and the supercooled liquid state up to 50°C by a time-of-flight method. The mobility (μh) in a single crystal was about 10−2 cm2/V.sec and its activation energies were 0.103 eV below 12°C and 0.037 eV above this temperature. A weakly endothermic solid phase transition was observed in a single crystal corresponding to this temperature. In the glassy state, μh was about 10−5 cm2/V.sec. In the supercooled liquid state, μh was also of the order of 10−5 cm2/V/sec and showed a maximum value at around 35°C, which appeared reproducibly and depended on the heating and cooling rate showing hysteresis phenomena. The Scher Montroll transport theory for non-crystalline solids could be applied to our material but in a rather limited temperature range.