Research On Current Gain And Fabrication Of Arrays Of Organic Photodiodes

Organic photodiodes(OPDs)have attracted widely attention due to the advantages of large-area fabrication,low-cost,flexibility and light-weighted,in which improving the quantum efficiency has been the research hotspot in organic devices and organic photodiode arrays is becoming a research focus because of its potential in imaging in recent years.To research on organic integrated devices and to explore the fabrication technics in this dissertation,firstly organic photodiodes with current gain were fabricated,and then different scales of planar-heterojunction organic photodiode arrays based on pentacene and copper phthalocyanine(Cu Pc),the two different organic light-sensitive semiconductor materials,were fabricated and characterized.The content of this paper is as follows.1.Organic photodiodes utilizing C₆₀:Pb Pc bulk-heterojunction as photosensitive layer and1,4,5,8-naphthalenetetracar-boxylic dianhydride(NTCDA)with different thicknesses as blocking layer were fabricated,in which the device with 3 nm thickness NTCDA can achieve the current gain,and shows highest photo responsivity of 2.22×10³ m A/W and external quantum efficiency of 420%at the applied voltage of-5 V and incident light power of 5.74 m W.2.Organic photodiode 3×2,4×3,5×4,6×5 arrays based on Cu Pc sensitive layer and pentacene were fabricated.The performance of the whole arrays and the OPDs in them was characterized.Firstly,organic photodiode 3×2 arrays based on pentacene sensitive layer and Cu Pc sensitive layer were compared and analyzed,which draws the conclusion that the Cu Pc array can work at a higher bias voltage,gains a higher ratio of the photocurrent to the dark current and have a higher uniformity and stability.And then organic photodiode 3×2,4×3,5×4,6×5 arrays based on pentacene sensitive layer were compared and analyzed,which draw the conclusion that the uniformity and stability of arrays reduces while the scale of arrays becomes larger.Finally,the relationship of dark current density and the scale of arrays was investigated and the analytical expression of them was proposed.