Synthesis and photoelectrical characterizations of ECPPQT for optoelectronic application

A new derivative of heteroannulated chromeno[2,3-b]pyridine identified as 5-ethyl-7H,9H-chromeno[3″,2″:5′,6′]pyrido[3′,2′:5,6]pyrano[3,2-c]quinoline-6(5H),7,9-trione (3) (ECPPQT) was easily and efficiently synthesized from DBU catalyzed condensation reaction of 2-aminochromone-3-carboxaldehyde (1) with 6-ethyl-4-hydroxy-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione (2). Structure of ECPPQT was deduced based on its correct elemental analysis and spectral data (IR, 1H NMR, and mass spectra). The X-ray diffraction patterns of TCVA in powder form show that there are several peaks with different intensities, indicating that the material has a polycrystalline nature. Optical absorption properties of ECPPQT thin films in near ultraviolet, visible and near infrared spectral regions showed characteristic absorption peaks. Optical absorptions were used to determine the characteristic band transitions in the range of 200–1100 nm. Two direct band gaps were calculated and found to be 1.85 and 3.30 eV for the optical and transport energy gaps, respectively. The ECPPQT/p-Si diode performs low photovoltaic characteristics with open circuit voltage of 330 mV, short-circuit current of 37 μA and fill factor of 33%. The phototransient measurements of the device indicate that the device has a good stability and quick response properties.