Photoluminescence of diamondoid crystals

Abstract

The photoluminescence of diamondoids in the solid state is examined. All of the diamondoids are found to photoluminesce readily with initial excitation wavelengths ranging from 233 nm to 240 nm ( 5.3 eV). These excitation energies are more than 1 eV lower than any previously studied saturated hydrocarbon material. The emission is found to be heavily shifted from the absorption, with emission wavelengths of roughly 295 nm (4.2 eV) in all cases. In the dissolved state, however, no fluorescence is observed for excitation wavelengths as short as 200 nm. We also discuss predictions and measurements of the quantum yield. Our predictions indicate that the maximum yield may be as high as 25%. Our measurement of one species, diamantane, gives a yield of 11%, the highest ever reported for a saturated hydrocarbon, even though it was likely not at the optimal excitation wavelength.

Anomalous fluorescence of the spherical carbon nitride nanostructures

“…This approach can also be used for milligram-scale synthesis of these water-soluble particles [25]. Measurement of one species, diamantane, gives a yield of 11%, which is the highest ever reported for a saturated hydrocarbon, even though it was probably not at the optimal excitation wavelength [26]. Different types of quantum dots have higher QY than that of s-C 3 N 4 .…”

Laser-induced fluorescence of free diamondoid molecules

“…The fluorescence spectra of crystalline diamondoids are found to be structureless with maxima around 295 nm, independent of their size and shape. 27 In a recent study, we presented size-and shape-dependent photoluminescence and excited state lifetimes for several diamondoids in the gas phase recorded using synchrotron radiation, 28 enabling us to resolve vibrational structure for several diamondoid molecules. However, due to the comparatively low fluence of the synchrotron light, excitation at the optical gaps was not always possible and prevented a resolution of the fine structure in some cases.…”

Derivatization of diamondoids for functional applications

“…[144][145][146] The inherent photoluminescence [149][150][151] and the tunable electronic properties [152][153][154] have also been applied in a wide range of new optical devices. Initially, the applications of diamondoids focused on taking advantage of the inherent properties of diamondoids, such as excellent mechanical/thermal properties and biocompatibility.…”

“…For instance, the optical gap of adamantane-1-thiol is 0.6 eV lower than that of adamantane. 151 The minimum excitation energy required for photoluminescence is significantly lower for adamantane than for other saturated hydrocarbons thanks to its unusually rigid structure. 148 This could be attributed to the recombination of self-trapped excitons.…”