H. Fujiyasu et al., PREPARATION OF CDSSE-ZNS SUPERLATTICE, SRS, AND CDSSE-SRS SUPERLATTICE BY HOT-WALL EPITAXY, AND APPLICATIONS TO ELECTROLUMINESCENT DEVICES, Journal of electronic materials, 22(5), 1993, pp. 545-550
CdSSe (manganese-doped, E(g) = 1.9-2.5 eV, lattice constant a = 6.05-5
.8A)-ZnS (Eg = 3.56 eV, a = 5.41A) superlattices, SrS (cerium-doped, E
(g) = 4.4 eV, a = 6.02A) layers, and CdSSe-SrS (cerium-doped) superlat
tice layers have been prepared by hot-wall epitaxy, and the properties
and the electroluminescent device characteristics of the active layer
s are reported. For the superlattices with ZnS, the maximum luminance
was 800 cd/M2 at an applied sinusoidal voltage (V(o-p) = 200 V) with f
requency 1kHz, and the wavelength of the spectral peak was 610 nm due
to the large strain caused by the lattice mismatch (8-15%) between the
CdSSe and ZnS layers. The maximum luminance and Comisson Internationa
le de Enluminure (CIE) chromaticity of CdS(Mn)-ZnS superlattices and C
dSe(Mn)-ZnS superlattice devices were 557cd/m2 and (x,y) = (0.58, 0.41
) and 982 cd/m2 and (0.61, 0.38), respectively. For superlattices with
SrS, the maximum luminance of the device with the SrS (cerium-doped)
active layer was nearly 700 cd/m2 at a voltage of 340 V. Blue electrol
uminescent emission was observed in the photon wavelength region less
than 450 nm, due to carriers dropping into the quantum wells of the de
vice with the CdSSe-SrS superlattice active layer.