Hybrid organic on inorganic semiconductor heterojunction

Hybrid organic on inorganic semiconductor heterojunctions with a sandwich structure have been fabricated and studied using conjugated polymers. The inorganic semiconductor was n-type silicon substrate. The conjugated polymers used include poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) containing polyhedral oligomeric silsesquioxanes (MEH-PPV POSS), regioregular poly(3-hexylthiophene) (RR-P3HT) and poly(3,4-ethylenedioxythiophene) (PEDOT). Current density-voltage and capacitance-voltage measurements were performed. All of the devices displayed a rectifying characteristic. Among these devices, the first ever reported PEDOT doped with BF3 on n-Si heterojunction devices showed the best performance with a rectification ratio around 5.7 x 10(5) at +/-2 V and an ideality factor of 2.3. The results showed better device performance with decreased potential barrier height at the organic-inorganic interface. Results also suggested that smaller energy level offset between the HOMO of the conjugated polymer and the work function of anode metal will improve device performance.