BS in Materials Engineering
Materials Engineering Department
Quantum dots have the ability to convert high energy photons into multiple lower energy photons. Down conversion of such high energy photons from sources such as UV light can be beneficial for applications on solar cells which waste much of the energy in the form of thermalization. To test this theory, a solar cell was hooked up to an Amprobe Solar Analyzer and tests were run to compare power output with and without the presence of quantum dots. Additionally, quantum dots were spin coated onto a glass wafer to determine its adhesion ability. Spectrometer readings were taken of the wafer after each spin coating cycle to measure any change in fluorescence. Power output of the solar cell without quantum dots was measured to be 224.1 mW while power output of the solar cell in the presence of quantum dots was 200.6 mW. Furthermore, spectrometer readings showed that no significant increase in fluorescence was gained after spin coating the glass wafer with quantum dots. These results led to the conclusion that the use of quantum dots suspended in a liquid medium are not effective in enhancing the performance of solar cells. Poor results may be due to the use of quantum dots emitting photons that still contain energy greater than the band gap of silicon. In addition, spin coating of the quantum dots is not a plausible method for application since very little adhesion took place. Lack of adhesion can be attributed to polar and non polar interaction between the glass wafer and quantum dots in octadecene respectively. Future steps include testing on a smaller scale using a silicon photodiode, using red quantum dots which contain photons closer to the silicon band gap, and suspending the dots in a different medium to help adhesion.