title: Tandem and triple-junction polymer:nanocrystal hybrid solar cells consisting of identical subcells.
abstract: Tandem and triple-junction polymer:nanocrystal hybrid solar cells with identical subcells based on P3HT:CdSe nanocrystal bulk heterojunctions (BHJs) are reported for the first time showing 2-fold and 3-fold increases of open-circuit voltage (VOC), respectively, relative to the single-junction cell. A combination of nanocrystalline ZnO and pH-neutral PEDOT:PSS is used as the interconnecting layer, and the thicknesses of subcells are optimized with the guidance of optical simulations. As a result, the average power conversion efficiency (PCE) exhibits a significant increase from 2.0% (VOC = 0.57 V) in single-junction devices to 2.7% (champion 3.1%, VOC = 1.28 V) in tandem devices and 2.3% (VOC = 1.98 V) in triple-junction devices.
authors.affiliation: Department of Chemistry and the Center for Energy Nanoscience, University of Southern California , Los Angeles, California 90089-0744, United States.
authors.forename: Haipeng
authors.initials: H
authors.lastname: Lu
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Bartynski
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Greaney
authors.forename: Mark E
authors.initials: ME
authors.lastname: Thompson
authors.forename: Richard L
authors.initials: RL
authors.lastname: Brutchey
keywords: CdSe; P3HT; hybrid solar cell; optical simulation; tandem solar cell