Study On Red-Light Organic Photodiodes Based On NdPc₂and ZnPc

Photodetectors are one of optoelectronic devices which converting the incident light signal into electrical signal. They have been widely applied in the defence science&technology and production&living. Organic photodetectors include organic photodiodes (OPD), photoresponsive organic field-effect transistors, organic photo-resistance and so on. Organic photodiodes have a broad application prospect due to their advantages, such as flexible choice of material, multiple preparation methods, broad response spectrum and adjustable working wavelength.In this thesis, we studied organic planar heterojunction photodiodes and organic superlattice photodiodes based on phthalocyanine neodymium (NdPc2) and phthalocyanine zinc (ZnPc).i. The NdPc2film thickness of the OPD based on NdPc2/C60planar heterojunction (NdPc2/C60-OPD) was optimized and found to be about20nm. When a reverse biased of5V was applied to the device, a dark current of3151.16μA and a photoresponsivity of1.92A/W were obtained.ii. The dark current of NdPc2(20nm)/C60(50nm)-OPD was decreased by19%after the anode and cathode of the device were modified by MoO3(molybdenum oxide,1nm) and LiF (lithium fluoride,1nm), respectively.iii. For the NdPc2(50nm)/C60(50nm)-OPD, both the dark current and the photoresponsivity of the devices were decreased with the annealed temperature increasing.iv. The superstructure photodiodes based on ZnPc (15nm)/C60(15nm) were fabricated. The maximum ratio of the photocurrent to the dark current of the device was increased with the periodicity of superstructure increasing, but the photoresponsivity of the device was decreased When the periodicity of superstructure was10cycles and a reverse biased of5V was applied to the device, a dark current of0.76μA, the maximum ratio of the photocurrent to the dark current of2101.99and a photoresponsivity of0.18A/W were achieved.