Luminescence of Long-Term Ordered Pure and Doped Gallium Phosphide

Abstract

Evolution of luminescence is reported from GaP crystals that were grown over 40 years ago. This is the longest running cycle of experiments to study the temporal effects of crystal lattice and impurity ordering. The results clearly indicate impurity ordering and the formation of a new type of crystal lattice in which periodically disposed impurities modify and improve properties of the crystal. A high-density exciton system bound to a nitrogen impurity superlattice and GaP:N, GaP:N:Sm nanocrystals distributed in transparent fluorine-containing polymers will be used as the base elements for a new generation of optoelectronic devices.

Time‐dependent evolution of crystal lattice, defects and impurities in CdIn2S4 and GaP

“…1a), microhardness and density of dislocations (Fig. 1b), we have established a tight connection between long-term evolution of optical and mechanical properties of GaP as well as a considerable difference in characteristics of freshly prepared and long-term ordered pure and doped crystals [6][7][8]. Note that we use the concept "freshly prepared" both for the crystals grown a long ago but investigated just after their preparation as well as for the crystals prepared and investigated at present.…”

“…The relevant data on GaP accumulated during the last decade are presented in [2][3][4][5][6][7][8]. Continuing in 2005-2008 the monitoring of GaP single crystals [3][4][5][6][7][8] grown 40-45 years ago from melted solution of 5% at. of P in Ga [9], we studied their properties that are changing with time, mainly, luminescence, Raman light scattering and microhardness in comparison with the data obtained from the same crystals since the 1960s [10][11][12][13][14] as well as with the properties of nanocrystals [4] and freshly prepared bulk single crystals of GaP [6,8].…”

“…Continuing in 2005-2008 the monitoring of GaP single crystals [3][4][5][6][7][8] grown 40-45 years ago from melted solution of 5% at. of P in Ga [9], we studied their properties that are changing with time, mainly, luminescence, Raman light scattering and microhardness in comparison with the data obtained from the same crystals since the 1960s [10][11][12][13][14] as well as with the properties of nanocrystals [4] and freshly prepared bulk single crystals of GaP [6,8]. We show that the long-term natural stimuli improving perfection of our crystals prevail over the others which could lead to heterogenic systems.…”

Excitonic Crystal and Nanotechnology

“…These, along with other half-centennial findings, including modifications to luminescence kinetics, spontaneous Raman scattering, x-ray diffraction, absorption spectra, micro-hardness and density of dislocations, that are reported elsewhere [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] strongly suggest that close-to-ideal GaP:N crystals are formed over time through the equally-spaced disposition of N impurities from their chaotic distribution in the same freshly prepared crystals.…”

“…Evaluation of the characteristic time of such reordering, based on the known Ising model, suggests that the time for the substitution reaction associated with N diffusion along P sites in GaP:N is about 15 years at room temperature [1]. Accordingly, observations of the luminescence from GaP:N crystals made at 10-15 year intervals under similar experimental conditions were used successfully to track such structural evolution [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. In this paper, as well as in the works published in 2012-2013 [14][15][16] we report the cumulative effects of over 50 years of lattice ordering on properties of GaP single crystals, providing clear evidence for enhanced optoelectronic properties through temporal dynamics over long time periods.…”