Characterizations And Applications Of Orgainc Opto-Couplers Based On Organic Heterojuctions

From 1940's,the development of information technology has been rapidly promoted.Due to the limitations of traditional inorganic electronic devices,the emerging organic electronics has been developed rapidly as a supplement.As a new organic semiconductor device,organic optocoupler(OOC),with good electric isolation and signal transport properties,has great potential in the future applications due to its low-cost and flexible property.In this paper,we mainly investigated the OOC based on the organic light-emitting diode(OLED)as the input unit and the organic photodiode(OPD)as the output unit.Issues on organic semiconductor,interface,and optical field distribution were also studied to explain the mechanism of exciton generation and carrier transmission.Via the efficiency improvement of each unit,high-performance OOCs were fabricated,based on which,we also develop the muti-functional applications.The main contents are as follows:1.Using the OPD based on m-MTDATA/C60 heterojuction as the photosensor unit and a blue OLED as the light source,we fabricated an OOC.Through the optical field simulation,we investigated the relationship between the OPD photocurrent and materials thickness.We also improve the OPD efficiency of carrier extraction and exciton dissociation by removing the Schotty barrier and adding the bulk-heterojunction.Light transimission efficiency was improved by using double-side ITO substrate.At last,based on the tandem OLED with extremely high light-emitting efficiency,the current transfer ratio(CTR)of2.2% was obtained,which was higher than some commercial inorganic optocouplers.In addition,the cut-off frequency and isolation voltage were increased to 250 k Hz and 3000 V by using the double-side ITO substrate.2.We used high-property photosensitive materials,ISQ,to fabricate better OOCs.The red OLEDs were used,and the CTR reached 4.4% through the optical field simulation and interfacial energy level modification.Meanswhile,by adding hole and electron blocking layers,the dark current decreased obviously.Thissort of OOC with red and near-infrared response can be applied in the future military field such as the night vision imaging and remote sensing.Then,based on the advantages of CH3NH3 Pb I3 such as high absorption in visible and near-infrared light,large carrier mobility and long diffusion length,we obtained a high efficiency OPD.Using a white tandem OLED as the light source,the photoresponsivity and CTR reached 1 A/W(@341.3 ?W/cm2)and263.3%,respectively.The CTR was the highest reported as far as we know.3.Because of the frequency response and electrical isolation properties of OOCs,we developed more applications,including low-voltage-control circuit,new method in carrier mobility measurement,and the pressure sensors.And combined with the triboelectric nano generator,a novel organic triboelectric optocoupler device was developed,which can relize the functions of intensity-and frequency-dependment signal transmission.These applications were expected to meet the demands in intelligent,personalized,portable and wearable devices in the future optoelectronics.