Electrical Tunability\nof Quantum-Dot-in-Perovskite\nSolids

The quantum-dot-in-perovskite matrix (DIM) is an emerging\nclass\nof semiconductors for optoelectronics enabled by their complementary\ncharge transport properties and stability improvements. However, a\ndetailed understanding of the pure electrical properties in DIM is\nstill in its early stage. Here, we developed PbS quantum dot-in-CsSnI<sub>3</sub> matrix solids exhibiting improved electrical properties and\nenhanced stability. PbS incorporation reduces the tensile strain of\nDIM films compared to that of pristine CsSnI<sub>3</sub>, consequently\nincreasing the electrical conductivity. Electrical conductivity is\ntunable between 20 and 130 S/cm as a function of PbS concentration.\nNotably, a decoupling of electrical conductivity and Seebeck coefficient\nis observed upon PbS addition into the perovskite matrix, which is\nattractive for thermoelectric applications. Density functional theory\nanalysis reveals that at low concentrations of PbS, light holes/electrons\ngovern the overall transport properties in DIM, while heavy holes/electrons\nbegin to dominate as the PbS concentration increases. Understanding\nthe electrical properties would help for designing DIMs with specific\nproperties for various technological applications.