Integrated NanoMaterials Laboratory

Nanomaterials and nanostructures grown in INML are used in lasers, solar cells, detectors, transistors, modulators, and a wide range of other electronic and photonic devices.



High efficiency Quantum dot solar cells

This word is aimed to develop ultra high efficiency solar cells based on self assembled quantum dot (QD) nanostructures. We are incorporating III-(As, Sb) quantum dots into the i-region of a p-i-n junction for multi-photon absorption. Based on theoretical predictions, these QD solar cells have potential for efficiencies greater than 50%. In this device, we utilize the unique benefits of an intermediate band formed by the electron levels in quantum dots. This device can produce not only high open circuit voltages (> 1.7 eV) but also large short-circuit currents due to the absorption of sub band gap photons. In the proposed structure, the barrier material can absorb wavelengths below 700 nm while multi-photon processes in quantum dots can be used to absorb wavelengths up to 2 µm. Our material flexibility can help tune the energy bandgap of the barrier material and quantum dot to their respective optimum values. This device is expected to outperform single or multi-junction solar cells in terms of energy conversion efficiency and cost. A key milestone towards achieving the claimed high-efficiency solar cell device is flexibly tuning the energy bandgap of the barrier material and QD according to the designed values.