Defect Structure Control And Property Study Of CuInS₂ Quantum Dots

Pure CuInS₂ quantum dots?CIS QDs?exhibit poor photoluminescence?PL?performance due to the presence of more dangling bonds on the surface.Therefore,it is necessary to coat the surface of pure CIS quantum dots to form core@shell structured QDs for protection.However,the conventional shells had a higher optical band gap than the pure CIS QDs,which caused the core@shell structured QDs showed a blue-shifted PL peak below 700 nm and narrower light absorption range.Herein,Zn and Al co-doped CIS quantum dots were synthesized by a simple cation exchange method.The main research results are summarized as follows:?1?The co-doped CIS quantum dots synthesized by one-pot method have a significant improvement in PL properties at about 740 nm compared to pure CIS quantum dots.The enhancement of PL performance may be attributed to Zn_Cu and Al_Cu defects in the co-doped CIS quantum dots,which could cause electron-hole radiation recombination through defect levels,reduce the number of dangling bonds and thus minimize the nonradiative recombination via surface electron trapping.In addition,through further analysis,it is also found that the PL intensity of the CIS quantum dot can be controlled by the doping reaction time.Within 30 minutes,the PL intensity of the CIS QDs samples increased as the doping reaction time increased.?2?The obtained deep-red emitting CIS QDs were further applied to the manufacture of semi-transparent luminescent solar concentrators?LSCs?which exhibited an excellent optical efficiency of 6.97%,and an overall power conversion efficiency of 3.18%.The success in using such Zn and Al co-doped CIS QDs could pave the way to realize high efficiency and environment-friendly LSCs for building integrated photovoltaics.?3?The pure CIS QDs synthesized by the hot injection method exhibited a red shift of the PL peak?180²30??when the reaction temperature was increased.Furthermore,after it was doped,as the doping time increased?1 h² h?,the PL intensity and anti-luminescence decay of the co-doped CIS QDs were enhanced.The PL performance of synthesized co-doped CIS QDs is significantly enhanced compared with pure CIS QDs.Therefore,the synthesized Zn and Al co-doped CIS QDs based CIS/PMMA LSCs are expected to get better performance.