02163nas a2200217   4500008004100000022001400041245015500055210006900210260000800279300001600287490000700303520136200310100002301672700002001695700001901715700002901734700002101763700001801784700001901802856012401821       2023                        eng d  a2050-748800aHigh open-circuit voltage in lead sulfide quantum dot solar cells <i>via</i> solution-phase ligand exchange with low electron affinity cadmium halides0 aHigh opencircuit voltage in lead sulfide quantum dot solar cells  cAUG  a17282-172910 v113 a<p>
	The deployment of colloidal quantum dots (QDs) in building high-performance solar cells and other optoelectronic applications relies on the passivation of unsaturated surface atoms through ligand engineering to attain a trap-free energy bandgap and strong QD coupling while maintaining the quantum confinement effect. Despite major advancements in surface passivation strategies, the open circuit voltage (V-oc) of lead sulfide (PbS) QD solar cells is limited by undesirable sub-bandgap states and high-bandtail states. The most advanced solution-phase ligand exchange strategy for PbS QDs depends on lead halide ligands, which improved the photocurrent and fill factor in QD solar cells significantly, but only an incremental change in V-oc is observed. Here we showcase a solution-phase hybrid ligand passivation strategy for PbS QDs using shallow electron affinity cadmium halide and thiol ligands. The cadmium halide ligand treatment results in the sub-monolayer substitution of surface Pb atoms by Cd atoms. The photophysical properties of QDs improve significantly to show intense band edge emission, diminished trap emission and reduced Urbach tail states. The photovoltaic devices built using cadmium halide-treated QDs show low reverse saturation current, which helps to attain a record 0.7 V V-oc (for a 1.28 eV bandgap) and 12.3% PCE.</p>
1 aDambhare, Neha, V.1 aBiswas, Arindam1 aSharma, Anjali1 aShinde, Dipak, Dattatray1 aMahajan, Chandan1 aMitra, Anurag1 aRath, Arup, K.  uhttps://library.ncl.res.in/content/high-open-circuit-voltage-lead-sulfide-quantum-dot-solar-cells-solution-phase-ligand