Luminescence of Mn4+ in a Zero-Dimensional Organic–Inorganic Hybrid Phosphor [N(CH3)4]2ZrF6 for Dual-Mode Temperature Sensing

Abstract

Searching for new low-dimensional organic–inorganic hybrid phosphors is of great significance due to their unique optical properties and wide applications in the optoelectronic field. In this work, we report a Mn4+ doped zero-dimensional organic–inorganic hybrid phosphor [N(CH3)4]2ZrF6, which was synthesized by a wet chemical method. The crystal structure, thermal stability, and optical properties were systemically investigated by means of XRD, SEM, TG-DTA, FTIR, DRS, emission spectra, excitation spectra, as well as decay curves. Narrow red emission with high color purity can be observed from [N(CH3)4]2ZrF6:Mn4+ phosphor, which maintains effective emission intensity even at room temperature, indicating its potential practical application in WLEDs. In the temperature range of 13–295 K, anti-Stokes and Stokes sidebands of Mn4+ ions exhibit different temperature responses. By applying the emission intensity ratio of anti-Stokes vs. Stokes sidebands as temperature readout, an optical thermometer with a maximum absolute sensitivity of 2.13% K−1 and relative sensitivity of 2.47% K−1 can be obtained. Meanwhile, the lifetime Mn4+ ions can also be used for temperature sensing with a maximum relative sensitivity of 0.41% K−1, demonstrating its potential application in optical thermometry.

Comparison of Performance between Single- and Multiparameter Luminescence Thermometry Methods Based on the Mn5+ Near-Infrared Emission

“…The great majority of luminescence thermometers that have been investigated so far rely on a single parameter to deliver an accurate temperature reading. The utilization of multiple thermometric parameters within the context of multimodal [19][20][21][22][23] or the multiparametric approach [24][25][26][27][28], on the other hand, has the potential to enhance the performance of thermometers. So far, the advantage of multiparametric thermometry has been realized through the application of multiple linear regression or similar statistical techniques and artificial neural networks [10,29,30].…”

Optical enhancement of highly efficient organic–inorganic oxyfluoride red phosphors via the cation co-doping strategy

“…12 In addition to the effective strategy of reducing the number of quenching centers, recently, attention has been paid to the preparation of new organic–inorganic matrix phases with diverse structures, high defect tolerance and high luminescence performance at room temperature. Currently, the few Mn 4+ -doped organic–inorganic fluoride/oxyfluoride materials reported can be mainly divided into two categories according to the types of organic cations, 4,6,13–17 (GA) x MF 6 (GA = C[NH 2 ] 3 + , x = 2, M = Ti 4+ , Si 4+ or Ge 4+ , x = 3, M = Al 3+ or Ga 3+ ) and (TMA) 2 NO y F 6− y :Mn 4+ (TMA = N[CH 3 ] 4 + , y = 0, N = Si 4+ , Ge 4+ , Ti 4+ or Zr 4+ , y = 2, N = W 6+ or Mo 6+ ). When Mn 4+ is doped equivalently in (GA) 2 SiF 6 and (GA) 2 TiF 6 , the [MnF 6 ] 2− octahedron is not distorted to produce zero-phonon line (ZPL) emission, but the fluorescence lifetime is generally long.…”