Hybrid gallium nitride/organic heterojunction with improved electrical properties for optoelectronic applications

The rectifying behavior and performance parameters of a hybrid organic/inorganic poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/Si-doped GaN layer (PEDOT:PSS/Si:GaN) are studied. The characteristics of both organic and inorganic layers have been individually examined, and a heterojunction between the same has been realized. AFM studies on optimized samples reveal low surface roughness (similar to 3.7 nm), and cross-sectional scanning electron microscopy images reveal uniform deposition of PEDOT:PSS layer over Si:GaN. The optimized heterojunction (thickness similar to 600 nm) presents a threshold voltage similar to 0.4 V with a rectifying behavior and a low ideality factor (n similar to 1.6) as compared to most of the related hybrid heterojunctions reported. The low ideality factor also points toward reduced trap-assisted tunneling and current leakage. A detailed comparison of heterojunction parameters including barrier height (I broken vertical bar (B)) of the samples and ideality factor is also presented.