Fabrication of an Organic/Inorganic Silicon Hybrid Solar Cell Based on PEDOT:PSS Doped and Non-Doped with CBP and Dibenzothiopene-Benzoyl-Tertiarybutylcarbozole

Novel organic semiconductor composite thin film doped with 40% and 50% dibenzo[b,d]thiophene-2-yl(4-(3,6-di-tert-butyl-9H-carbozl-9-yl)phenyl) (DBT-BZ-tBuCz) in (4,4 '-di(9H-carbazol-9-yl)-1,1 '-biphenyl) (CBP) and methanone solution was prepared in dichloromethane (DCM) using the spin-coating process. The band energy recorded for DBT-BZ-tBuCz solutions was 3.79 eV which is less than the electron affinity of n-Si (4.03 eV). This lower band energy proved the advantage of the combined CBP and DBT-BZ-tBuCz:DCM system. The CBP and DBT-BZ-tBuCz:DCM thin film was also coated with poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/Si to form an organic/C-Si/organic structure. It was observed that the open-circuit voltage and the fill factor of the solar cell device improved significantly with coating; a relative increase of 75% power conversion efficiency was noted. Further, the results indicated that the increase in high power conversion efficiency value is attributable to the reduction of recombinative and resistive losses at the rear side of the device, which contributed to the efficient electron-selective CBP in combination with DBT-BZ-tBuCz:DCM contact. Furthermore, the developed solar cell device is economical, inexpensive, and efficient. It has been concluded that these thin films can be used as selective electronic contacts to customize the energy band structure in currently dopant-free silicon (Si) heterojunction solar cells.