Quantum dots (QD) are sub-microscopic semiconductor particles with dimensions typically in the range of a few nanometers. Due to their diminutive size, they exhibit distinct optical and electrical properties compared to their larger counterparts, thereby forming a fundamental building block in the field of nanotechnology. By supplying electricity or light to diverse types of quantum dots, they emit light at specific frequencies, and the precision of this frequency can be controlled by varying the size, shape, and composition of the dots. This remarkable attribute of quantum dots presents a vast array of potential applications across various industries. In order to capture more solar spectrum in the near infrared area, QDot PbS QDs can be used in solar cells. QDs are promising for tandem solar cells constructed with different materials, such as silicon or perovskite solar cells, because their absorbance wavelength in the NIR range can be adjusted. A standalone PbS solar cell under development has already attained 10% certified efficiency.  https://nantronics.in/