- Identifying defects by imaging stress fields in c-Si wafers
Silicon is naturally abundant and provides advantages for solar cell applications. These advantages have led to a current share of the PV market greater than 85%, however, the cost of crystalline silicon (c-Si) based PV modules must be reduced by 2–3x to enable widespread grid penetration. Guided by a cost-performance model, we focus our R&D efforts in three key areas: (1) increasing conversion efficiency; (2) reducing the amount of silicon used in the wafer; and (3) decreasing manufacturing costs.
- Reactive sputtering of cuprous oxide thin films
Photovoltaic devices based on thin-film absorbers promise to substantially reduce the cost of solar cells. The primary savings come from the smaller volume of material needed for the active layers, monolithic integration of modules, and the lower energy budget for growth. Focusing on Earth-abundant materials which are plentiful enough to scale up production to produce terawatts of power. We work on two fronts in this field. The first is enhancing the efficiency of currently deployed or close-to-commercial technologies. The second is establishing basic physical properties of novel material systems and developing efficient devices from these materials.
- Nanosecond laser pulse for characterizing HD-Si films
Today’s commercially produced solar cells are limited to maximum theoretical efficiency around 30% by the fact that the semiconductor material absorbing the light can only utilize a fraction of the incident solar radiation. Furthermore, because they only produce power during the day, there is an inherent need for energy storage. We are working to radically improve the energy conversion efficiencies of photovoltaic devices beyond existing and near-commercial technologies by engineering the band structures of photovoltaic materials to efficiently absorb greater portions of the solar spectrum and using advanced optics to split the solar spectrum into color bands. We are also designing PV materials and devices for water splitting to store solar energy efficiently as hydrogen.