@article {48701,
	title = {Multi-bandgap quantum dots ensemble for near-infrared photovoltaics},
	journal = {Energy Technology},
	volume = {11},
	year = {2023},
	month = {JUN},
	type = {Article},
	abstract = {<p>
	Narrow bandgap quantum dots (QDs) are an important class of materials for near-infrared (NIR) optoelectronic devices owing to their size-tunable bandgap and chemical root processing. In photovoltaic applications, NIR QDs could be particularly useful to complement the sub-bandgap transmission loss of NIR solar radiation from perovskite and c-Si solar cells. However, insufficient carrier extraction thickness associated with the narrow NIR excitonic bandwidth of QDs limits the conversion efficacy of the broad NIR solar spectrum. Here, we utilize a multi-bandgap QD ensemble which widens the NIR absorption bandwidth to mimic the broad solar spectrum. A solution-phase ligand passivation strategy is used to control doping properties and energy level alignment of multi-bandgap QDs. We successfully developed bulk-heterojunction solar cells using the multi-bandgap QD ensemble, which yields higher carrier extraction thickness and broader NIR absorption. The gain from NIR absorption and carrier transport resulted in higher short-circuit current generation and power conversion efficiency (PCE) in solar cell devices. The champion device shows 8.73\% PCE under 1.5 AM solar illumination and 7.44\% and 5.05\% PCE for the NIR photons transmitted from perovskite and c-Si layers.</p>
},
	keywords = {bulk-heterojunctions, multi-bandgap, near-infrared, quantum dots, solar cells, surface passivation},
	issn = {2194-4288},
	doi = {10.1002/ente.202201375},
	author = {Mahajan, Chandan and Dambhare, Neha V. and Biswas, Arindam and Sharma, Anjali and Shinde, Dipak Dattatray and Rath, Arup K.}
}
@article {49328,
	title = {Synthesis and processing strategy for high-bandgap PbS quantum dots: a promising candidate for harvesting high-energy photons in solar cells},
	journal = {ACS Applied Materials \& Interfaces},
	volume = {16},
	year = {2024},
	month = {AUG },
	pages = {42522-42533},
	type = {Article},
	abstract = {<p>
	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.</p>
},
	keywords = {charge transport, lead sulfide, ligand passivation, quantum dots, solar cell},
	issn = {1944-8244},
	doi = {10.1021/acsami.4c09364},
	author = {Shinde, Dipak Dattatray and Sharma, Anjali and Dambhare, Neha V. and Mahajan, Chandan and Biswas, Arindam and Mitra, Anurag and Rath, Arup K.}
}
