Research On The Fabrication And Properties Of 2,6-diphenylanthracene Thin-film Transistors

The tremendous advances in organic semiconductors(OSCs),charge transport physics of OSCs and device fabrication have brought in a great progress in the field of organic thin-film transistors(OTFTs)in the past three decades.OTFTs are promising in display backplane drivers,RFID tags,they also show great potential in functional devices like photoelectric sensors,pressure sensors,memories,flexible circuits and so on.However,numerous laboratory efforts are needed before commercial outcomes of OTFTs can be achieved.The integrated development of materials,physics and devices are the key point to promote the advancement of the field of OTFTs.Now,serious of OSCs with brilliant TFT mobility have been designed and synthesized,some of them have exceeded the amorphous silica.In addition,great research advances have been made in charge transport physics of OSCs.Therefore,it is important to fully explore the potential of existing OSCs to fabricate high performance OTFT on the basis of existing theory.And then good performance OTFTs can stimulate the development of materials and theory in reverse,realizing the advancement of the OTFTs filed.This thesis is based on 2,6-diphenylanthracene,a p-type small molecular semiconductor with excellent optical and electrical properties,using thermal evaporation as film deposition method,to explore the influence of film deposition parameters on the properties of DPA OTFT.8 types of DPA thin-film have been deposited with the rate range from 0.01 (?)/s to 3.00 (?)/s to elucidate the influence of deposition rate on figures of merit other than mobility of OTFTs,including the variation of threshold voltage and transfer curve hysteresis of DPA OTFTs.We analyzed the properties changes of OTFTs,taking advantage of the trap theory of OSCs,and carried out characterizations for DPA thin-film,including X-ray diffraction,Atomic Force Microscope and Ultraviolet Photoelectron Spectroscopy,to support the hypothesis.As a result,we demonstrated that the regular variation of threshold voltage and transfer curve hysteresis of DPA OTFTs is due to different trap densities in different DPA thinfilm,which is formed during the thin-film deposition.Our work will provide guidance for the improvement of OTFTs based on DPA and its analogues,and also pave the way for the development of functional DPA OTFTs or OTFTs with DPA based composite semiconductor layer.