03405nas a2200229 4500008004100000022001400041245021300055210006900268260000800337300001600345490000800361520247400369100002702843700002202870700003402892700001802926700001902944700002602963700003002989700002703019856012903046 2020 eng d a1932-744700aUnsymmetrical squaraine dyes for dye-sensitized solar cells: position of the anchoring group controls the orientation and self-assembly of sensitizers on the TiO2 surface and modulates its flat band potential0 aUnsymmetrical squaraine dyes for dyesensitized solar cells posit cAUG a18436-184510 v1243 a

The position of the anchoring group is systematically changed with a series of alkyl group wrapped donor-acceptor-donor (D-A-D) based squaraine dyes, 4-SQ to 7-SQ, for the use in dye-sensitized solar cells (DSSCs). By this approach, the orientation as well as the self-assembly of the sensitizers can be controlled on the semiconducting TiO2 surface. All of the dyes functionalized with hydrophobic alkyl groups at sp(3)-C and N atoms of the indoline units that is far away from the TiO2 surface to control the self-assembly of dyes and passivate the surface. Controlling both the orientation as well as the self-assembly of the sensitizers synergistically enhances the V-oc of the DSSC device by imparting the dipole moment on the TiO2 surface and minimizing the interfacial charge recombination process of electrons from TiO2 to the oxidized electrolyte, respectively. Further, the presence of a meta-carboxyl group with respect to the N atom of the indoline donor unit for the dyes 4-SQ and 6-SQ makes them nonconductive for the charge injection process, which sheds light on the importance of through-space electron transfer for the device performance. Emission from the relaxed twisted state was found to be a deactivation pathway for 4-SQ on TiO2 and ZrO2, which revealed the importance of structural factors that promote spatial interaction between the sensitizer and metal oxide surface. Computational studies showed the systematic changes in the dipole moment for the sensitizers 4-SQ, 5-SQ, and 6-SQ upon anchoring to the TiO2 surface. The DSSC device performance varied with the position of anchoring groups in the sensitizers. The DSSC device performance of 5-SQ indicates a J(sc) value of 11.35 mA cm(-2), V-oc of 0.698 V, and ff of 77% corresponding to a power conversion efficiency of 6.08% in the presence of 3 equiv of coadsorbent CDCA, which is nearly 1.5 times higher than 6-SQ (V-oc 0.7 V, J(sc) 7.76 mA cm(-2), ff 76%, and eta 4.14%) and 2.6 times higher than 4-SQ (V-oc 0.658 V, J(sc) 4.42 mA cm(-2), ff 78%, and eta 2.28%). IPCE studies revealed the importance of orientation for the charge injection and self-assembly of dyes, as devices with 5-SQ and 6-SQ as a sensitizer showed 94 and 77% response at 578 nm, respectively, which correspond to the aggregated structure of the dye. Mott-Schottky and IPCE experiments showed that the orientation of sensitizers could modulate the V-oc due to the shift in the flat band potential of TiO2.

1 aSingh, Ambarish, Kumar1 aMaibam, Ashakiran1 aJavaregowda, Bharathkumar, H.1 aBisht, Rajesh1 aKudlu, Ashwath1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/unsymmetrical-squaraine-dyes-dye-sensitized-solar-cells-position-anchoring-group-controls02145nas a2200277 4500008004100000022001400041245008300055210006900138260000800207300001400215490000700229520124200236100002101478700003301499700002301532700002301555700002301578700001901601700001901620700002401639700002801663700002401691700001701715700002001732856011501752 2025 eng d a1948-718500aSupercooled liquid phases of luminescent zero dimensional metal halide hybrids0 aSupercooled liquid phases of luminescent zero dimensional metal  cSEP a9391-94000 v163 a

Chemical design of metal halide hybrids (MHHs) with suppressed melting point (T-m) allows access to glassy phases from their liquid-melts. Thermal phase change (crystal-melt-glass) properties of glassy MHHs (with glass transition temperature T-g > room temperature) have been exploited for device applications. However, room temperature stable supercooled liquid (SCL) MHHs (with T-g < room temperature), originating from glass-SCL phase change, remain inaccessible. Here, a molecular design strategy is reported to access ambient stable, melt-processable, SCL multimetallic bromide hybrids (Mn2+,Cd2+; Mn2+,Zn2+; Benzyltributylammonium) with low T-g (15-16 degrees C), low T-m (90-100 degrees C), green luminescence, and high optical transparency. Structural, optical, thermal, and computational analyses highlight chemical design principles and support dopant (Mn2+) based luminescence. Rheological measurements confirm the SCL phase that shows thermal hysteresis and estimate relaxation time scales. This work provides a new material platform showcasing enhanced melt-processability for fabrication of moldable devices, unravelling chemical makeup-property correlation and expanding the material phase types of MHHs.

1 aDas, Deep, Kumar1 aMarayathungal, Jumana, Hasin1 aPalakkolil, Athira1 aSarma, Dhritismita1 aKhan, Akram, Aadil1 aKumar, Praveen1 aKudlu, Ashwath1 aChoudhary, Mahendra1 aHathwar, Venkatesha, R.1 aPujala, Ravi, Kumar1 aMahata, Arup1 aKundu, Janardan uhttps://library.ncl.res.in/content/supercooled-liquid-phases-luminescent-zero-dimensional-metal-halide-hybrids02622nas a2200253 4500008004100000022001400041245017400055210006900229260000800298300001400306490000700320520168000327100002102007700002302028700001902051700002302070700002902093700001902122700004002141700002402181700001702205700002002222856012602242 2026 eng d a0897-475600aBright dual-phase organic luminescence from zero-dimensional lead halide hybrids via sensitized thermally activated delayed fluorescence for multifunctional applications0 aBright dualphase organic luminescence from zerodimensional lead  cMAY a4668-46810 v383 a

Metal halide hybrids have long celebrated their halometallate moieties as the luminescent center, leaving organic cations behind. Although the thermally activated delayed fluorescence (TADF) strategy has enabled efficient solid-state organic emitters, the complex molecular design required for TADF emitters has limited their facile integration into metal halide hybrid architectures. Here, we demonstrate a versatile strategy wherein a nonemissive organic moiety (benzyltributylammonium) is incorporated into a zero-dimensional disphenoidal Pb-halide hybrid, [(C19H34N)2PbCl4], resulting in efficient TADF-based dual-phase organic emission sensitized by halometallate units in the solid state (crystalline; amorphous). These materials exhibit strong PLQY (similar to 85%) and tunable organic luminescence (blue emission in crystalline phase; cyan emission in amorphous phase) modulated by the packing extent of organic moiety. [PbX4]2- units act as absorptive centers that sensitize organic cations showing TADF-based strong emission. Ground and excited state density functional theory calculations reveal the unique origin of sensitized TADF organic luminescence. Rheological measurements characterize relaxation dynamics of glass <-> supercooled liquid transitions, establishing correlations between molecular packing, phase, and emission characteristics. This first demonstration of dual-phase, sensitized TADF-based organic luminescence in lead halide hybrids establishes a new design paradigm that bridges molecular and solid-state photophysics, opening avenues for multifunctional applications in LEDs, optical thermometry, and security technologies.

1 aDas, Deep, Kumar1 aSarma, Dhritismita1 aKumar, Praveen1 aKhan, Akram, Aadil1 aMadhusoodhananan, Mahesh1 aKudlu, Ashwath1 aAjithkumar, Thalasseril, Govindanku1 aPujala, Ravi, Kumar1 aMahata, Arup1 aKundu, Janardan uhttps://library.ncl.res.in/content/bright-dual-phase-organic-luminescence-zero-dimensional-lead-halide-hybrids-sensitized