Description

This fellowship opportunity focuses on advancing new photovoltaic technologies based on organic and inorganic/organic bulk heterojunctions. These technologies are attractive due to their potential for low-cost, high-volume manufacturing via roll-to-roll processing. However, the simplicity of processing leads to challenges in controlling the nanoscale morphology of the films, which critically affects charge separation and harvesting efficiency.

The research aims to develop and apply measurement techniques, particularly small angle scattering methods, to evaluate the buried architecture of bulk heterojunction photovoltaic films. NIST has developed a unique small angle X-ray scattering (SAXS) instrument capable of characterizing domain shape, size, and location across length scales from microns to Angstroms. Grazing-incidence SAXS will probe in-plane structures, while transmission SAXS will assess through-plane structures. Complementary wide-angle X-ray diffraction can provide information on grain size and crystallinity within domains. Additionally, small angle neutron scattering (SANS) with selective deuteration enhances contrast in soft domains.

The goal is to correlate the detailed microstructure and morphology of these films with photovoltaic cell performance, thereby guiding the design and fabrication of more efficient organic and hybrid solar cells.

Keywords

Microstructure, Morphology, Nanostructure, Organic electronics, Photovoltaic, Polymer, Scattering, Semiconductor