Highly luminescent broadband phosphors based on acid solvent coordinated two-dimensional layered tin-based perovskites

Abstract

Lead-based perovskites which show remarkable photophysical characteristics have become revolutionary semiconductor materials for optoelectronic fields. However, the lead in their chemical compositions limits commercial application. Herein, ODASnBr4 (ODA denotes protonated...

Spacer Switched Two-Dimensional Tin Bromide Perovskites Leading to Ambient-Stable Near-Unity Photoluminescence Quantum Yield

“…As discussed earlier, one of the major drawbacks of Sn-based perovskites is their unstable nature because of the self-oxidation of Sn 2+ . Recently, proton donors in the form of alcohols, dichloromethane, and chloroform have been used to stabilize the 2D phase and to attain an appreciable PLQY. , Acid precipitation with varying amounts of HBr and H 3 PO 2 have also resulted in ∼98% PLQY of ODASnBr 4 but without any confirmed stability . Our trick was to use an excess of H 3 PO 2 as the reducing agent that helped to stabilize the Sn 2+ state.…”

“…In fact, the PL intensities continue to increase linearly with the excitation power (Figure S9b). Similar to the continuous-wave (CW) laser excitation used in conventional PL measurements, ,, the high repetition rate of 80 MHz pulsed excitation in our PL experiments allows the attainment of a steady-state population density for the STE, bound, and free excitons. The steady-state population density depends on the photocarrier generation rate which is essentially governed by the excitation intensity and the lifetime of the various states involved in the PL emission.…”

“…13,25 Acid precipitation with varying amounts of HBr and H 3 PO 2 have also resulted in ∼98% PLQY of ODASnBr 4 but without any confirmed stability. 26 Our trick was to use an excess of H 3 PO 2 as the reducing agent that helped to stabilize the Sn 2+ state. Even though the excess organic ligands and acids can act as impurities that further degrade the structure and hence the PLQY, we have ensured an extensive washing by ether and chloroform to remove such impurities.…”

Spacer Switched Two Dimensional Tin Bromide Perovskites Leading to Ambient Stable Near Unity Photoluminescence Quantum Yield

“…13,25 Acid precipitation with varying amounts ofHBr and H3PO2 have also resulted in ~98% PLQY of ODASnBr4 but without any confirmed stability. 26 Our trick was to use an excess of H3PO2 as the reducing agent that helped to stabilize the Sn 2+ state. Even though the excess organic ligands and acids can act as impurities that further degrade the structure and hence the PLQY, we have ensured an extensive washing by ether and chloroform to remove such impurities.In our case, the sublime stabilities of PL emission and absolute PLQY is an outstanding result owing to the protection of the inorganic SnBr6 4blocks with 91 wt% Sn 2+ state by the hydrophobic long-chain 1,8 diammonium octane cation.…”

“…In fact, the PL intensities continue to increase linearly with the excitation power (Figure S9b). Similar to the continuous-wave (CW) laser excitation used in conventional PL measurements, 13,25,26 the highrepetition rate of 80 MHz pulsed excitation in our PL experiments, allow the attainment of a steady-state population density for the STE, bound and free excitons. The steady-state population density depends on the photocarrier generation rate which is essentially governed by the excitation intensity, and lifetime of the various states involved in the PL emission.…”