|About this Abstract
||2011 TMS Annual Meeting & Exhibition
||Surfaces and Heterostructures at Nano- or Micro-Scale and Their Characterization, Properties, and Applications
||Controlling Defect Density in Polymer-Fullerene Bulk Heterojunction Solar Cells by Optimizing Growth Conditions
||Kanwar Nalwa, Rakesh Mahadevapuram, Yuqing Chen, Santosh Pandey, Sumit Chaudhary
|On-Site Speaker (Planned)
Although promising, the performance of polymer:fullerene bulk-heterojunction solar cells is still limited by several factors including recombination at interfacial states. Hence, it is important to study and quantify the factors that govern the density of defects states (DODS). To understand the effect of growth rate on the DODS of poly(3-hexyl thiophene (P3HT) based solar cells, three types of P3HT:fullerene cells (A, B, and C) were fabricated with growth rate (solvent drying time upon spin coating) of ~ 40, 7 and 1 minutes, respectively. Capacitance and sub-band gap characterizations showed that slowest growth of device A led to reduction of DODS by an order of magnitude as compared to fastest grown device C. The slow growth assists the formation of self-organized ordered structure in the P3HT/fullerene blend system diminishing morphological defects. These observations were also confirmed by analysis of dark current-voltage curves.
||Planned: A CD-only volume