Research On Fabrication And Performance Of Doped Organic Semiconductor Devices

In recent years,organic semiconductor materials have been rapidly developed due to their large-area and flexible preparation characteristics.As a means of regulating the optoelectronic properties,doping is adopted and promoted gradually.However,the research on the doping mechanism and doping methods of organic semiconductors still faces many difficulties and bottlenecks.For example,the physical mechanism of doping organic semiconductors is not completely clear.The performance of organic semiconductor devices decreased after excessive doping.In this paper,we focused on the doping effect of a new dopant,TrTPFB（Trityltetrakis（pentafluorophenyl）borate）,on the classic P-type organic polymer semiconductor poly（3-hexylthiophene）（P3HT）.We used doping as an entry point to control the electrical properties of P3HT.We want to realize the regulation and improvement of the performance of organic field-effect transistors（OFET）and perovskite solar cells（PSC）devices.The specific research content is as follows:（1）We blended P3HT with TrTPFB solution to prepare a doped solution and spin-coated it to form thin films.We found that the organic salt TrTPFB can dope P3HT effectively through a series of electrical and optical tests.The conductivity of the P3HT thin film increased from 2×10^-3 S/cm to 5 S/cm at 2.5 mol%doping ratio,which is four orders of magnitude higher than the original P3HT.（2）Based on the above work,we used TrTPFB to prepare doped P3HT organic field-effect transistors.By adjusting the doping ratio,it is found that a proper amount of doping can increase the mobility of OFETs effectively.The mobility of the undoped device,1.1×10^-3 cm²/（V·s）,can be increased to 1.5×10^-3 cm²/（V·s）at a 2 wt%doping ratio.However,the organic field-effect transistor loses its modulation effect in the case of excessive doping.（3）We tried to use doped P3HT with different doping concentrations as the hole transport layer（HTL）in PSC based on the above studies.It is found that under the optimal doping condition（0.5 mol%）,the photoelectric conversion efficiency（PCE）of the PSC is as high as 11.17%,which is 12.4%higher than the device using the original P3HT as the HTM.The research results and methods of this paper are helpful to promote the research and application of doping technology in organic semiconductors and provide a new method for the preparation of high-performance OFET and PSC devices.