10.1021/acsami.9b03528.s001 Wenli Zhou Wenli Zhou Ren-Hong Wang Ren-Hong Wang Lichang Yin Lichang Yin Jun Chen Jun Chen Chaochin Su Chaochin Su Xianran Xing Xianran Xing Ru-Shi Liu Ru-Shi Liu Alcohol-Guided Growth of Two-Dimensional Narrow-Band Red-Emitting K<sub>2</sub>TiF<sub>6</sub>:Mn<sup>4+</sup> for White-Light-Emitting Diodes American Chemical Society 2019 prototype phosphor-converted LED photoluminescence quantum efficiency Mn alcohol-assisted coprecipitation route 1- propanol efficacy K 2 TiF 6 MSs Two-Dimensional Narrow-Band Red-Emitting K 2 TiF 6 morphology-optimal KTFM MSs red-emitting K 2 TiF 6 QE 2019-05-09 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Alcohol-Guided_Growth_of_Two-Dimensional_Narrow-Band_Red-Emitting_K_sub_2_sub_TiF_sub_6_sub_Mn_sup_4_sup_for_White-Light-Emitting_Diodes/8159096 The use of red phosphors with low light-scattering loss could improve the luminous efficacy and color rendering of white-light-emitting diodes (LEDs). Thus, the discovery of such phosphors is highly desired. In this work, high-efficiency two-dimensional red-emitting K<sub>2</sub>TiF<sub>6</sub>:Mn<sup>4+</sup> (KTFM) were synthesized via an alcohol-assisted coprecipitation route. The synergistic effects of 1-propanol and hydrofluoric acid on the growth of KTFM microsheets (MSs) were studied through the first-principles calculations, which revealed that 1-propanol promoted the growth of KTFM MSs by preferentially adsorbing on the H-terminated K<sub>2</sub>TiF<sub>6</sub> (001) surface. The photoluminescence quantum efficiency (QE) of Mn<sup>4+</sup>-activated K<sub>2</sub>TiF<sub>6</sub> MSs was highly related to their size and thickness. The morphology-optimal KTFM MSs presented high internal QE (>90%), external QE (>71%), and thermal quenching temperature (102% at 150 °C relative to that at 25 °C). A prototype phosphor-converted LED with KTFM as the red-emitting component showed excellent color rendition (<i>R</i><sub>a</sub> = 91, <i>R</i>9 = 79) and high luminous efficacy (LE = 156 lm/w).