Electroluminescence in thin solid films of closely packed CdS nanocrystals

Abstract

Millisecond kinetics of photo-darkening/bleaching in xGe45Se55-(1−x)As45Se55 chalcogenide amorphous films J. Appl. Phys. 112, 053105 (2012) Analysis of sub-stoichiometric hydrogenated silicon oxide films for surface passivation of crystalline silicon solar cells J. Appl. Phys. 112, 054905 (2012) Phase evolution and room-temperature photoluminescence in amorphous SiC alloy J. Appl. Phys. 111, 103526 (2012) Resistive switching properties of amorphous Pr0.7Ca0.3MnO3 films grown on indium tin oxide/glass substrate using pulsed laser deposition method Thin solid films of closely packed CdS nanocrystals with sizes between 1.5 and 1.8 nm have been prepared and sandwiched between indium-tin-oxide ͑ITO͒ and silver contacts. At room temperature, these CdS nanocrystals start to emit light visible to the unaided eye at a bias above 15 V. The spectral characteristics are voltage controlled and tunable between 1.8 eV and 2.8 eV with increasing bias from 20 to 40 V. The current-voltage dependence indicates hopping conductivity of the carriers injected. At high voltage the electroluminescence and photoluminescence spectra are similar showing a strong red shift of the luminescence maximum with respect to the absorption peak at 3.75 eV which we explain by an effective radiative recombination through deep traps in the interface region. Consequently, the tunability of electroluminescence is attributed to excitation of different deep traps by electron transport across neighbouring CdS nanocrystals. © 1997 American Institute of Physics. ͓S0021-8979͑97͒06410-4͔

Fabrication of CdS/Cd–Sn heterostructure nanowires and their photoluminescence property

“…As an important II-VI semiconductor, CdS nanowires have attract considerable interests in optoelectronic applications because of its band-gap energy (2.52 eV) in the visible region. CdS nanowires have been demonstrated attractive physical properties including nanoscale lasers, optical waveguides, photosensors and photodetectors [9][10][11][12][13][14]. Recently, some researchers have found heterostructure nanowires can exhibit better performance in physical properties than the homostructures [15][16][17][18].…”

Preparation, characterization and growth mechanism study of CdS/Cr nanostructures

“…As an important II-VI group semiconductor material, CdS has a band-gap energy of 2.42 eV, and is used for a host of applications in optoelectronics [1], such as nonlinear optics, flat panel displays, light emitting diodes, lasers, and thin film transistors [2][3][4][5][6][7]. In recently, the researchers have reported that the structure of CdS played an important role on the influence of the unique physical properties of CdS.…”

Ageing and temperature‐dependent behaviour of CdS nanoparticles

“…The study of size-dependent optical properties of nanoparticles has become the topic of both experimental and theoretical interest [1][2][3]. The physical properties that are intermediate between those corresponding to the bulk semiconductors and the molecular structures have attracted researchers for extensive studies and have revealed many new facts.…”