02397nas a2200289 4500008004100000245009400041210006900135260000900204300001400213490000600227520146100233653002401694653001701718653002301735653002601758653001801784653001601802100002001818700001801838700001901856700002901875700001901904700001901923700002101942700001901963856012501982 2024 eng d00aSolution-phase ligand engineering for all-quantum-dot near-infrared light-emitting diodes0 aSolutionphase ligand engineering for allquantumdot nearinfrared  cAPR  a9126-91350 v73 a

Strong emission over a wide near-infrared (NIR) region makes lead sulfide quantum dots (QDs) a preferred material in building NIR light-emitting diodes (NIR-LEDs) for numerous applications. Narrow-bandgap emitter QDs blended in the matrix of high-band gap QDs offer a simple yet powerful architectural platform for building high-performance NIR-LEDs. So far, the all-QD-based blend architecture has been realized using a poorly controlled solid-state ligand exchange approach. Advanced solution-phase ligand exchange, which offers greater control over surface passivation, is yet to be realized in all-QD LED device construction. We observe that the solution-phase ligand exchange from the optimized lead halide and thiol ligand combination, used in high-performing QD solar cell construction, is inefficient in realizing efficient all-QD LEDs, which could have restricted the adoption of the solution-phase ligand exchange thus far. Here, we introduce an innovative dual-ligand strategy to build all-QD-based NIR-LEDs using an advanced solution-phase ligand exchange approach. Through ligand engineering of matrix QDs, we managed to improve photoluminescence quantum yield (40%), reduce trap density (10(14) cm(-3)), and prolong carrier lifetime (832 ns). The LED devices benefit from improved electronic properties and balanced carrier injection to yield 6% EQE and 7.7% PCE, which are six times higher than those of state-of-the-art ligands.

10aelectroluminescence10alead sulfide10aligand passivation10alight-emitting diodes10anear-infrared10aquantumdots1 aBiswas, Arindam1 aMitra, Anurag1 aSharma, Ashish1 aShinde, Dipak, Dattatray1 aDambhare, Neha1 aSharma, Anjali1 aMahajan, Chandan1 aRath, Arup, K. uhttps://library.ncl.res.in/content/solution-phase-ligand-engineering-all-quantum-dot-near-infrared-light-emitting-diodes02379nas a2200277 4500008004100000022001400041245014500055210006900200260000900269300001600278490000700294520143500301653002101736653001701757653002301774653001701797653001501814100002901829700001901858700002301877700002101900700002001921700001801941700001901959856012301978 2024 eng d a1944-824400aSynthesis and processing strategy for high-bandgap PbS quantum dots: a promising candidate for harvesting high-energy photons in solar cells0 aSynthesis and processing strategy for highbandgap PbS quantum do cAUG  a42522-425330 v163 a

The wide tunability of the energy bandgap of colloidal lead sulfide (PbS) quantum dots (QDs) has uniquely positioned them for the development of single junction and tandem solar cells. While there have been substantial advancements in moderate and narrow bandgap PbS QDs-ideal for single junction solar cells and the bottom cell in tandem solar cells, respectively; progress has been limited in high-bandgap PbS QDs that are ideally suited for the formation of the top cell in tandem solar cells. The development of appropriate high bandgap PbS QDs would be a major advancement toward realizing efficient all-QD tandem solar cells utilizing different sizes of PbS QDs. Here, we report a comprehensive approach encompassing synthetic strategy, ligand engineering, and hole transport layer (HTL) modification to implement high-bandgap PbS QDs into solar cell devices. We achieved a greater degree of size homogeneity in high-bandgap PbS QDs through the use of a growth retarding agent and a partial passivation strategy. By adjusting the ligand polarity, we successfully grow HTL over the QD film to fabricate solar cells. With the aid of an interface modifying layer, we incorporated an organic HTL for the realization of high-performance solar cells. These solar cells exhibited an impressive open-circuit voltage of 0.824 V and a power conversion efficiency of 10.7%, marking a 360% improvement over previous results.

10acharge transport10alead sulfide10aligand passivation10aquantum dots10asolar cell1 aShinde, Dipak, Dattatray1 aSharma, Anjali1 aDambhare, Neha, V.1 aMahajan, Chandan1 aBiswas, Arindam1 aMitra, Anurag1 aRath, Arup, K. uhttps://library.ncl.res.in/content/synthesis-and-processing-strategy-high-bandgap-pbs-quantum-dots-promising-candidate03163nas a2200301 4500008004100000022001400041245017900055210006900234260000800303300001400311490000700325520211500332653001702447653002302464653001802487653001702505653001502522653002102537100001902558700002902577700002102606700002302627700002002650700001802670700002502688700001902713856012902732 2025 eng d a1944-824400aSynergistic improvement of narrow bandgap PbS quantum dot solar cells through surface ligand engineering, near-infrared spectral matching, and enhanced electrode transparency0 aSynergistic improvement of narrow bandgap PbS quantum dot solar  cJAN a6614-66250 v173 a

The tunability of the energy bandgap in the near-infrared (NIR) range uniquely positions colloidal lead sulfide (PbS) quantum dots (QDs) as a versatile material to enhance the performance of existing perovskite and silicon solar cells in tandem architectures. The desired narrow bandgap (NBG) PbS QDs exhibit polar (111) and nonpolar (100) terminal facets, making effective surface passivation through ligand engineering highly challenging. Despite recent breakthroughs in surface ligand engineering, NBG PbS QDs suffer from uncontrolled agglomeration in solid films, leading to increased energy disorder and trap formation. The limited NIR transparency of commonly used indium-doped tin oxide (ITO) electrodes and inadequate NIR radiation from commercially available solar simulators further compromise the true performance of NBG PbS QDs in solar cells. Here, we employ a hybrid ligand strategy based on inorganic cadmium halide and organic thiol molecules, leading to the partial substitution of surface Pb atoms with Cd heteroatoms. This hybrid ligand strategy substantially reduces undesired QD fusion in solid films, improving the photophysical and electronic properties. By modulating the thickness of the ITO layer and managing refraction loss through a ZnO layer coating, we improved NIR transparency to above 80%. We combine an NIR light source with a solar simulator to achieve near-ideal spectral matching for a broader range with standard AM1.5G illumination. Enhancements in surface passivation of QDs, improvements in NIR transparency of electrodes, and a spectral matched light source setup help us achieve solar cell power conversion efficiencies of 12.4%, 4.48%, and 1.37% under AM 1.5G, perovskite filter, and silicon filter illuminations, respectively. A record open-circuit voltage (V oc) of 0.54 V and short-circuit current density (J sc) of 38.5 mA/cm2 are achieved under AM 1.5G illumination. We attribute these advancements in photovoltaic parameters to the reduction in Urbach tail states and intermediate trap density originating from superior surface passivation of QDs.

10alead sulfide10aligand passivation10anear-infrared10aquantum dots10asolar cell10atandem solarcell1 aSharma, Anjali1 aShinde, Dipak, Dattatray1 aMahajan, Chandan1 aDambhare, Neha, V.1 aBiswas, Arindam1 aMitra, Anurag1 aGirade, Vrushali, S.1 aRath, Arup, K. uhttps://library.ncl.res.in/content/synergistic-improvement-narrow-bandgap-pbs-quantum-dot-solar-cells-through-surface-ligand