02151nas a2200229   4500008004100000022001400041245009400055210006900149260000800218300001600226490000700242520140100249653001101650653001301661653001601674653001501690653002401705100002201729700002701751700001901778856012401797       2019                        eng d  a1944-824400aThiol and halometallate, mutually passivated quantum dot ink for photovoltaic application0 aThiol and halometallate mutually passivated quantum dot ink for   cJUL  a26100-261080 v113 a<p>Tunable-band-gap colloidal QDs are a potential building block to harvest the wide-energy solar spectrum. The solution-phase surface passivation with lead halide-based halometallate ligands has remarkably simplified the processing of quantum dots (QDs) and enabled the proficient use of materials for the development of solar cells. It is, however, shown that the hallometalate ligand passivated QD ink allows the formation of thick crystalline shell layer, which limits the carrier transport of the QD solids. Organic thiols have long been used to develop QD solar cells using the solid-state ligand exchange approach. However, their use is limited in solution-phase passivation due to poor dispersity of thiol-treated QDs in common solvents. In this report, a joint passivation strategy using thiol and halometallate ligand is developed to prepare the QD ink. The mutually passivated QDs show a 50% reduction in shell thickness, reduced trap density, and improved monodispersity in their solid films. These improvements lead to a 4 times increase in carrier mobility and doubling of the diffusion length, which enable the carrier extraction from a much thicker absorbing layer. The photovoltaic devices show a high efficiency of 10.3% and reduced hysteresis effect. The improvement in surface passivation leads to reduced oxygen doping and improved ambient stability of the solar cells.</p>
10aligand10amobility10aquantum dot10asolar cell10asurface passivation1 aMandal, Debranjan1 aGoswami, Prasenjit, N.1 aRath, Arup, K.  uhttps://library.ncl.res.in/content/thiol-and-halometallate-mutually-passivated-quantum-dot-ink-photovoltaic-application