Park Receives Utah NASA Space Grant Consortium Training Grant
April 10, 2015
For his research, which aims to implement photoconductive atomic force microscopy (pc-AFM) that enables the nanoscale photocurrent mapping of a thin-film solar cell, mechanical engineering assistant professor Keunhan Park received a one-year $22,948 grant from the Utah NASA Space Grant Consortium Training Grant.
Photovoltaic (PV) energy conversion is one of NASA’s energy-related research directions, as solar energy is a primary energy source for their missions. As a strategic approach to push the current PV technology to the next generation, thin-film solar cells made of emerging semiconductor
materials, such as CdTe and perovskites, have received a keen attention from the PV community.
However, the microscopic mechanisms of photocurrent generation, transport, and dissipation
across grain boundaries and defects of these materials are not well understood to date although this
understanding is critically important to make high efficient solar cells. To address this challenge,
the proposed research aims to implement photoconductive atomic force microscopy (pc-AFM)
that enables the nanoscale photocurrent mapping of a thin-film solar cell. To accomplish the
research goal, we propose (1) to integrate the optical access of an external light source with
conductive atomic force microscopy (c-AFM) and (2) to achieve the nanoscopic image of
photocurrent-voltage (I-V) spectrum for a CdTe solar cell and compare the image with the
topography. The obtained results will provide the first set of data that helps us understand the
correlation of photocurrent generation with the microstructures and compositions of a CdTe solar
cell. In addition, we will also explore the effect of near-field light illumination onto the
photocurrent generation by exciting localized surface plasmons at the metallic tip, which
concentrates the electromagnetic field at the tip apex to form a subwavelength light spot.
Learn more about Dr. Park and his research at Micros/Nanoscale Energy Transport & Conversion Labortory