Effect of traps on the charge transport in semiconducting polymer PCDTBT. (July 2018)

• Record Type: Journal Article
• Authors: Khan, Mohd Taukeer; Agrawal, Vikash; Almohammedi, Abdullah; Gupta, Vinay
• Is Part Of: Solid-state electronics. Volume 145(2018)
• Page Start: 49
• Page End: 53
• Publication Date: 2018-07
• Subjects: Traps -- Organic semiconductors -- PCDTBT -- Trap density -- Hole mobility -- Space charge limited current; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2018.04.005
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: At room temperature, J(V) characteristics of PCDTBT follow Mott-Gurney square law. For the lower temperatures, J(V) characteristics follow trap-filling SCL law. Switching of charge transport from trap-free to trap-filling SCLC observed at 12 V. Mobility of trap-free region is one order higher than the trap-filling region. Abstract: Organic semiconductors (OSCs) are nowadays called upon as promising candidates for next generation electronics devices. Due to disorder structure of these materials, a high density of traps are present in their energy band gap which affect the performance of these devices. In the present manuscript, we have investigated the role of traps on charge transport in PCDTBT thin film by measuring the temperature dependent J(V) characteristics in hole only device configuration. The obtained results were analyzed by space charge limited (SCL) conduction model. It has been found that the room temperature J(V) characteristics follow Mott-Gurney square law for trap-free SCL conduction. But below 278 K, the current increases according to trap-filling SCL law with traps distributed exponentially in the band gap of semiconductor. Furthermore, after reaching a crossover voltage of VC ∽ 12 V, all the traps filled by injected carriers and the trap-filling SCL current switch to trap-free SCL current. The hole mobility of trap-free SCL current is about one order higher as compared trap-filling SCL current and remains constant with temperature.