“Building molecules is like playing with building blocks, putting them together in interesting ways. I feel like there’s a beauty in them.”
Beauty – and utility. The molecules Jorge Wu Mok “plays” with are conjugated polymers. With them the sixth-year doctoral student in chemical and biomolecular engineering (ChBE) at Rice University designs stretchable, malleable photovoltaics for the conversion of solar energy into electricity.
“It’s a promising option for supplying renewable clean energy on a global scale. We want to harvest sunlight, especially with the price of oil always fluctuating,” said Mok, a member of the research group headed by Rafael Verduzco
, associate professor of ChBE.
Block copolymers, which self-assemble into ordered nanostructures, are used to regulate the morphology of the structures. Controlling their shape and form at the nanoscale reduces the macro-phase separation, which leads to improvements in the efficiency of organic semiconductor-based devices.
“We have been focusing on their efficiency,” Mok said. “We’ve made them lightweight and flexible. Now we are also working to make them more mechanically robust. Solar cells tend to break or crack. We are working on finding the optimal chemistry.”
Small molecule additives are incorporated into solar cells to enhance their robustness, improving their resistance to environmental stresses and increasing their useful longevity.
Another goal is lowering the cost of manufacturing the solar cells. “We are considering printing the photovoltaic material directly on to surfaces or applying it as a spray, even on moving parts,” he said. “We foresee the possibility of wearable solar cells, as on a watch.”
Mok has a varied academic background, appropriate preparation for research that draws on many disciplines. He earned a B.S. in chemical engineering and a B.A. in mathematics, with a minor in physics, from the State University of New York at Buffalo in 2012.
After graduation, Mok came to Rice in 2012 and has worked as a research affiliate at the Center for Functional Nanomaterials at Brookhaven National Laboratory, and at the Center for Nanomaterials and the Advanced Photon Source at Argonne National Laboratory.
Mok was born in Rio de Janeiro, Brazil, where his parents had settled after leaving China. The arrangement left him fluent in English and Portuguese, and conversant in Spanish and Cantonese.
“Even before I came to Rice I wanted to work with Prof. Verduzco. The work he is doing is the reason I chose to come to Rice,” Mok said.