Photoluminescence spectra of polycrystalline ZnSe in different experimental geometries

Temperature behaviour of the photoluminescence spectra of polycrystalline ZnSe films with different surface treatment

“…A wide PL emission band with the maximum located at 630 nm is clearly seen in Fig. 5a at the temperature equal to 13 K. Our results agree very well with the data reported at 300 K in the work [15], where the half-widths of the band detected at 13 K and 300 K are equal respectively to 0.48 eV and 0.56 eV (with the energy difference 0.08 eV). When the temperature increases from 13 to 280 K, the initial PL spectra displayed in Fig.…”

“…One of the results of Ref. [15] and the present work can be of a particular and independent interest. It is the green band observed in the PL spectrum under conditions when the He-Cd laser (λ ex =325 nm, i.e.…”

“…hv ex >E g ) excites polycrystalline CVD ZnSe from the unpolished surface either at the room temperature (as in Ref. [15]) or in the temperature range 12-300 K (as in the present work). In the future, this result can be used when creating green LEDs based on polycrystalline CVD ZnSe.…”

“…Indeed, when the temperature increases up to 280 K, the intensity of the green band changes, contrary to the intensities of the other peaks. The peaks located at 443, 588, 650, 668, 707 and 728 nm have earlier been discussed by us [15]. They can be called as 'spurious'.…”

“…It is important that the temperature dependences of luminescence in ZnSe crystals have been often examined either near 4 K or in a narrow temperature region around this point [6][7][8][9][10][11][12]. The role of surface in the luminescent processes has been studied recently in the works [13][14][15]. The analysis for the temperature behaviour of luminescent properties in relation to the surface structure of crystalline substances (e.g., thin films or grains of powder phosphors) is also of great interest.…”