The Simulation Research Of Colloidal PbSe Quantum Dots Luminescent Solar Concentrator

Luminescent solar concentrator(LSC) is a kind of concentrator photovoltaic which canreduce the cost of solar photovoltaic by replacing a large area expensive solar cell with asimple structure by the method of spotlighting. Organic dyes were often chosen asfluorescent dye of LSC by researchers in the past, but their shortcomings such as narrowabsorption spectrum, strong reabsorption, instability, short fluorescence lifetime havehindered the improving of LSC’s efficiency. Colloidal quantum dots(QDs) have becomehotspot materials in recent years. Compared to traditional organic dyes, they have moreexcellent optical characteristics such as tunable absorption emission spectra, high quantumyield, weak reabsorption, preferable stability, long fluorescence lifetime and so on. In orderto improve LSC’s cost-efficacy, we apply2.8nm colloidal PbSe QDs to LSC.In this paper, we have analyzed the composition of exciton energy of QDs, andcombined finite potential well model with effective mass approximation, to set up acomputational model to calculate band gap of PbSe QDs. The calculated values show a goodfit to the experimental results. Then we have synthesized colloidal PbSe QDs with differentsizes with Yu’s method. We have evaluated their structure and composition using TEM andXRD, and measured their absorption spectra and PL spectra. It shows that the band gap ofPbSe QDs is size-dependent and the quantum yield is over80%. Next we have analyzed thetheory of LSC in detail, including the process of photon conversion in LSC, transmissionmode of fluorescence in LSC, the theories of reabsorption and reemission, transmission lossof fluorescence and so on, and set up a mathematical model of LSC. Based on themathematical model, a software is developed to simulation LSC on Microsoft Visual C++6.0. According to experimental data, we have simulated2.8nm colloidal PbSe QDs LSC. Theinfluence of LSC’s size on LSC’s efficiency, geometric concentrating ratio andincome parameter was researched through simulation, and the optimum size was found.Under the optimum size, the influence of PbSe QDs’s concentration on LSC’s efficiency wasresearched, and the optimum concentration was found. Finally, we have found the LSC withgood performance, its length of sides are150cm×200cm, thickness of interlayer is1mm,PbSe QDs’s concentration is2.5×10-5mol/L, LSC’s efficiency is3.25%, geometricconcentrating ratio is61.224and income parameter is12.436. It shows that colloidal PbSeQDs can improve LSC’s cost-efficacy, also it’s the ideal fluorescent dye of LSC.