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1) To develop and screen ligands with different anchoring groups for low-dimensional white-light emitting perovskite.

2) To study the photophysical properties of perovskites in thin films based on developed ligands.

3) To grow the single crystals of the white-light emitting perovskites and to study and compare the photophysical attributes in thin film with those obtained for single crystals.

4) To investigate the mechanism of white-light emission from the perovskite.

5) To apply the developed perovskites for ultraviolet light simulated white-light-emitting LED.

Lighting constitutes the major sector that consumes 1/5th of the global energy, leaving a mammoth footprint of over 1900 metric tons of CO2. The technology of light-emitting diodes (LEDs) underpins the most promising for lighting and display applications due to the energy efficiency and high quality that the technology could offer to significantly cut down the energy spent on the lighting sector. In 2024, the commercial solid-state lighting market worthed a value of 15.9 billion, which demanded a fast-paced growth of sustainable, cost-effective, and energy-efficient technologies to meet UN SDG goal 7 of affordable and clean energy for the global citizen. The lack of red emissive components in the GaN-YAGbased lighting technology offers a poor color rendering index (CRI). Similarly, with organic light-emitting diodes (OLEDs)-based lighting technology, utilization of less than 10% of the material during vacuum deposition and the expensive nature of organic electroluminescent material renders the technology less promising and expensive. Therefore, in the realm where energy efficiency, cost-efficiency, and lighting quality together contribute to concerning factors in deciding the impact and success of technologies for lighting and display applications, organic-inorganic hybrid perovskites exhibited tremendous potential to emerge as a promising material for lighting technology of the future owed to inexpensive precursor, easy scalability, excellent optoelectronic properties, and self-emissive propensity typically lacking with other contemporary technologies or solid-state lighting materials. However, low stability to ambient conditions remains a bottleneck in 3D-perovskites that withholds the fast-paced commercial prospect of perovskite-based LEDs (PeLEDs). In this regard, low-dimensional perovskites stand tall due to the inherent stability that could be imparted by bulky organic linkers. If a judiciously designed organic linker is explored for organic-inorganic hybrid perovskites, white-light emitting perovskites could be synthesized cost-efficiently for lighting applications attributed with high emission propensity due to the high binding energy of excitons. Further, lattice engineering could bestow emission from different states depending upon exciton-phonon couplings. Therefore, in light of the great prospects of white-lightemitting perovskites for solid-state lighting applications, herein under this project, we propose to develop low-dimensional white-light emitting perovskites by judicious linker designing that could make possible exciton phonon coupling. The developed white-light emitting perovskite would be investigated for photophysical and emission attributes for ultimate applications in UV-light excited white-light emitting LED prototype. Also, the mechanism behind white-light emission from these perovskites will be studied in-depth under this proposal.
 

1) Broadband emission in the range 400-700 nm

2) PLQY in the range of 80-90%

3) Binding energy>350 meV

4) CIE coordinate close to 0.33, 0.33; CCT in the range of 3000-4000 K: CRI> 80

5) Luminnace efficiency >100 lm/watt

6) High-impact publications

7) A technology of white-light emitting perovskite-based lighting.

8) A white-light emitting prototype

The solid-state lighting market is expected to burgeon at a CAGR of 14.04% till 2029 and stable energyefficient technologies are in huge demand owing to this market expansion.2 To meet the demand and supply, India is primarily sourcing phosphors-based materials for solid-state lighting applications from countries like Japan, Germany, China, rendering India among the top three global importers of phosphorbased materials for lighting applications. Further, a look at the key players of solid-state lighting markets shows that the top companies are from different countries other than India:

• Signify NV (Netherlands)

• ams Osram GmbH (Germany)

• Wolfspeed (USA)

• Nichia corporation (Japan)

• Samsung Electronics co. Ltd (South Korea)

Therefore to expand footprint in the sector of solid-state lighting, India needs to develop in-house capabilities that can allow self-reliance. Also, to avoid the import of phosphor-based sources or materials an alternative promising technology could be offered by exploring perovskite-based lighting. The major advantages of exploring perovskites for lighting applications include : the low-cost of precursors, easy processability, tunable broadband emission, easy to attain CCT, CRI, and CIE that could be attained based on ligand engineering or halide exchange. However instead of all these promising attributes, the commercialization of perovskite-based lighting is yet to be achieved globally, primarily due to the concerns of low material stability. Nevertheless, this low ambient stability issues of 3Dperovskites could be addressed when low-dimensional perovskites are judiciously designed and explored for lighting applications. Therefore, dedicated research activity to develop and engineer lowdimensional perovskites for solid-state lighting applications is indeed a need of the hour when lab-toland translation of perovskite-based lighting is the aim that could bring a renaissance in the sector of solid-state lighting.