Tarak Nath Mandal

Chemically tuned inorganic-organic hybrid materials, based on CH3NH3(═MA)Pb(I(1-x)Br(x))3 perovskites, have been studied using UV-vis absorption and X-ray diffraction patterns and applied to nanostructured solar cells. The band gap engineering brought about by the chemical management of MAPb(I(1-x)Br(x))3 perovskites can be controllably tuned to cover almost the entire visible spectrum, enabling the realization of colorful solar cells. We demonstrate highly efficient solar cells exhibiting 12.3% in a power conversion efficiency of under standard AM 1.5, for the most efficient device, as a result of tunable composition for the light harvester in conjunction with a mesoporous TiO2 film and a hole conducting polymer. We believe that the works highlighted in this paper represent one step toward the realization of low-cost, high-efficiency, and long-term stability with colorful solar cells.

The photovoltaic performance of Sb2 Se3 -sensitized heterojunction solar cells, which were fabricated by a simple deposition of Sb2 Se3 on mesoporous TiO2 by an approach that features multiple cycles of spin coating with a single-source precursor solution and thermal decomposition, is reported. Poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothioadiazole)] was used as the hole-transporting material. The most efficient cell exhibited a short-circuit current density of 22.3 mA cm(-2) , an open-circuit voltage of 304.5 mV, and a fill factor of 47.2 %, yielding a power conversion efficiency of 3.21 % under standard test conditions (irradiation of 1000 W m(-2) , air mass=1.5 G). The results of this study imply that the developed approach has a high potential as a simple and effective route for the fabrication of efficient and inexpensive solar cells.

Hybrid bromide perovskites (HBPs) have emerged as a promising candidate in optoelectronic applications, although instability of the materials under working conditions has retarded the progress toward commercialization. As a rational approach to address this core issue, we herein report the synthesis of a series of ultrastable composite materials, wherein HBP nanocrystals (NCs) have been stabilized within a well-known chemically stable metal–organic framework (MOF) viz. zeolitic imidazolate framework (ZIF-8) via a pore-encapsulated solvent-directed (PSD) approach. The composites maintain their structural integrity as well as photoluminescence (PL) properties upon dipping into a wide range of polar solvents including water (even in boiling conditions), prolonged exposure to UV irradiation, and elevated temperature for longer periods of time. Further, on the basis of high stability, HBP@MOF composites have been demonstrated as heterogeneous photocatalysts to degrade toxic organic pollutants directly in water.

A Sb2(S1-x/Sex)3 graded-composition is obtained by a sequential deposition of Sb2S3 and Sb2Se3 onto a mesoporous TiO2 photoelectrode followed by thermal annealing at 300 °C. The compositional graded-solar cells exhibit a greatly enhanced performance compared to pristine Sb2S3-sensitized or Sb2Se3-sensitized solar cells. The best performing cell, delivering an incident-photon-to-current efficiency extended to 1050 nm, exhibits an overall power conversion efficiency of 6.6% under simulated illumination.