Study On Photoelectric Properties Of PTCDI-C13 N-channel Thin-Film Organic Field-Effect Phototransistor

Organic phototransistor is an important category of organic filed effect transistors,which density of charge carrier could be changed by light.Organic field-effect phototransistors?OFETs?have attracted a great deal of interest because their outstanding advantages of organic materials such as the good flexibility,light weight,low fabrication,and so on.And they can achieve light detection,light switching and signal magnification in a single device.Above all strengths make OPTs show their great potential applications in wearable devices,flexible display devices and health monitoring.Although OPTs have achieved great progress over the last decades,some limitations are still remaining in this research field,which including:?i?Until now,most of researches are related to the study of p-channel materials,but only a few studies have focused on n-channel materials.This unbalanced research situation for OPTs can restrict their applications in complementary electronics and optoelectronic circuits.?ii?The photosensitivity of numerous n-channel organic materials are inferior,which ranging from 79 to 104.While the highest photosensitivity demonstrated for p-channel OPTs is over 109.The photosensitivity is one of the crucial parameters connected with digital circuits and pixel switches,where a high photosensitivity can effectively avoid misreading binary data.It is desirable to improve the photosensitivity of n-channel OPTs.?iii?Reports on conformal OPTs are scarce.However,conformal OPT is essential for OPTs,because it shows the unique and important advantages of OPTs.Bad air stability and optoelectronic characteristics are the main limitations of n channel organic phototransistors.To overcome these limitations,we carry out lots of experiments and get the statistical data to choose the right dielectric?silicone?and we fabricate good-performance n-channel OPTs based on silicone and commercialized PTCDI-C13materials.Furthermore,we insert an additional a semiconductor material named Alq3.Based on PTCDI-C13 and Alq₃ materials,high-photosensitivity organic heterojunction phototransistors are fabricated,and we make some work in conformal OPTs.The main results of this paper are followed:1.Organic thin-film phototransistors were fabricated vacuum deposition on PMMA?PVA?PDMS and Sillicone dielectric layers.Silicone layer was selected as dielectric layer because of its great stability and conformal ability.We carry out lots of experiments and get the statistical data to select PTCDI-C13 as semiconductor from PTCDI-C8 and PTCDI-C13.By choosing and optimizing different dielectric and semiconductor materials,we fabricated n-channel PTCDI-C13 OPTs and we make detailed study on optoelectronic performance of OPTs.These devices exhibit excellent stability and good optoelectronic performance and show good potentiality in light detection.2.Based on good performance of n-channel PTCDI-C13 OPTs,we inserted an additional Alq₃ layer and optimized PTCDI-C13/Alq₃ heterojunction to improve the photosensitivity of OPTs.The spectral absorption range of the organic thin film is broadened and the P value can be improved by over 2 orders of magnitude by inserting an Alq3 layer.Under illumination at a wavelength of 489 nm with a light intensity of 243?Wcm^-2,the average P value of PTCDI-C13/Alq3 OPTs is over 10⁵.Meanwhile,we explained the reason why the photosensitivity of OPTs is improved after inserting Alq₃ layer by discussing the changes of parameter after inserting Alq3 and varied their thickness.We provides a good method for fabricating high-performance n-channel conformal OPTs.3.Conformable n-channel OPTs with high P value were fabricated by peeling off from the substrate.The OPTs show great ability of adherence,it can be adhered on different surface such as uneven surface,human eye mode and so on.When it was adhered on human eye mode,conformable n-channel OPTs with high P value are demonstrated and the P value of devices almost remained few changes before and after adherence.P values of all transistors before and after adherence are higher than 10⁵,and they remained few changes after adherence,which shows promising potential for detecting light signals.