TY - JOUR
T1 - Thin-film transistor as a probe to study carrier transport in amorphous organic semiconductors
AU - So, Shu K.
AU - Choi, Wing H.
AU - Cheung, Chi H.
N1 - Funding Information:
Support of this research by the Research Committee of Hong Kong Baptist University and the Research Grant Council of Hong Kong under Grant No. FRG2/09–10/077 and HKBU211209E are gratefully acknowledged.
PY - 2011
Y1 - 2011
N2 - We describe how to use the thin-film transistor (TFT) technique to quantify carrier transport of amorphous organic semiconductors relevant to organic electronic devices. We have chosen several amorphous materials, including arylamine compounds, 4,4'-N,N'-dicarbazole-biphenyl (CBP), and a phosphorescent dye molecule [Ir(ppy)3] for investigations. Generally, the field effect (FE) mobility was found to be about one order of magnitude smaller than that obtained from an independent time-of-flight (TOF) technique. For N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) and N,N'-Bis(3-methylphenyl)-N,N'-bis(phenyl)-9,9-spirobifluorene (spiro-TPD), the FE mobilities were found to be 1.7×10-5 and 1.3 ×10 -5cm2/Vs, respectively. Temperature-dependent measurements were carried out to study the FE mobility. It was found that the energetic disorder increased in the neighborhood of a gate dielectric layer. This factor is one of the origins causing the discrepancy between TFT and TOF mobilities. We also examined how the hole transport of CBP is affected by Ir(ppy)3 when it is doped into CBP.
AB - We describe how to use the thin-film transistor (TFT) technique to quantify carrier transport of amorphous organic semiconductors relevant to organic electronic devices. We have chosen several amorphous materials, including arylamine compounds, 4,4'-N,N'-dicarbazole-biphenyl (CBP), and a phosphorescent dye molecule [Ir(ppy)3] for investigations. Generally, the field effect (FE) mobility was found to be about one order of magnitude smaller than that obtained from an independent time-of-flight (TOF) technique. For N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) and N,N'-Bis(3-methylphenyl)-N,N'-bis(phenyl)-9,9-spirobifluorene (spiro-TPD), the FE mobilities were found to be 1.7×10-5 and 1.3 ×10 -5cm2/Vs, respectively. Temperature-dependent measurements were carried out to study the FE mobility. It was found that the energetic disorder increased in the neighborhood of a gate dielectric layer. This factor is one of the origins causing the discrepancy between TFT and TOF mobilities. We also examined how the hole transport of CBP is affected by Ir(ppy)3 when it is doped into CBP.
KW - Hole transports, 4,4'-N,N'-dicarbazole-biphenyl (CBP)
KW - Organic light-emitting diodes (OLEDs)
KW - Thin-film transistors
KW - Tris(2-phenylpyridine) iridum [Ir(ppy)]
UR - http://www.scopus.com/inward/record.url?scp=84870616775&partnerID=8YFLogxK
U2 - 10.1117/1.3534200
DO - 10.1117/1.3534200
M3 - Journal article
AN - SCOPUS:84870616775
SN - 1947-7988
VL - 1
JO - Journal of Photonics for Energy
JF - Journal of Photonics for Energy
IS - 1
M1 - 011011
ER -
