scholarly journals Luminescence from Erbium-Doped Gallium Nitride Thin Films

1999 ◽  
Vol 4 (S1) ◽  
pp. 926-932
Author(s):  
J. M. Zavada ◽  
Myo Thaik ◽  
U. Hömmerich ◽  
J. D. MacKenzie ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Thin Films ◽  
Elevated Temperatures ◽  
Light Emission ◽  
Thermal Quenching ◽  
Emission Spectra ◽  
Light Emitting Devices ◽  
Recent Developments ◽  
Device Applications ◽  
Er Doped

The III-V nitride semiconductors appear to be excellent host materials for optical device applications involving thin films doped with rare earth atoms. In particular, GaN epilayers doped with Er ions have shown a highly reduced thermal quenching of the Er luminescence intensity from cryogenic to elevated temperatures. The remarkable thermal stability of the light emission may be due to the large energy bandgap of the material, as well as to the optical inactivity of material defects in the GaN film. In this paper we present recent developments concerning the luminescence characteristics of Er-doped GaN thins films. We have used two methods for doping GaN films with Er ions, ion implantation and in-situ incorporation during gas source metal-organic molecular beam epitaxy (MOMBE). Bandedge (at ∼ 0.34 µm) and infrared (at ∼ 1.54 µm) photoluminescence (PL) spectra have been measured for both types of Er-doped GaN films. Considerably different emission spectra have been observed depending upon the incorporation method and the heat treatment procedure. In situ Er-doped GaN layers have been processed into hybrid light emitting devices and emission spectra at 1.54 µm have been measured.

Luminescence from Erbium-Doped Gallium Nitride Thin Films

1998 ◽  
Vol 537 ◽  
Author(s):  
J. M. Zavadat ◽  
Myo Thaik ◽  
U. Hòmmerich ◽  
J. D. MacKenzie ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Thin Films ◽  
Elevated Temperatures ◽  
Light Emission ◽  
Thermal Quenching ◽  
Emission Spectra ◽  
Light Emitting Devices ◽  
Recent Developments ◽  
Device Applications ◽  
Er Doped

AbstractThe III-V nitride semiconductors appear to be excellent host materials for optical device applications involving thin films doped with rare earth atoms. In particular, GaN epilayers doped with Er ions have shown a highly reduced thermal quenching of the Er luminescence intensity from cryogenic to elevated temperatures. The remarkable thermal stability of the light emission may be due to the large energy bandgap of the material, as well as to the optical inactivity of material defects in the GaN film. In this paper we present recent developments concerning the luminescence characteristics of Er-doped GaN thins films. We have used two methods for doping GaN films with Er ions, ion implantation and in-situ incorporation during gas source metal-organic molecular beam epitaxy (MOMBE). Bandedge (at ∼ 0.34 μm) and infrared (at ∼ 1.54 μm) photoluminescence (PL) spectra have been measured for both types of Er-doped GaN films. Considerably different emission spectra have been observed depending upon the incorporation method and the heat treatment procedure. In situ Er-doped GaN layers have been processed into hybrid light emitting devices and emission spectra at 1.54 Pm have been measured.

Tuning optical properties of CsPbBr3 by mixing Nd3+trivalent lanthanide halide cations for blue light emitting devices.

2022 ◽  
Author(s):  
Muhammad Amin Padhiar ◽  
Minqiang Wang ◽  
Yongqiang Ji ◽  
Zhi Yang ◽  
Arshad Saleem Bhatti
Keyword(s):  
Optical Properties ◽  
Blue Light ◽  
Light Emission ◽  
Low Cost ◽  
Thermal Quenching ◽  
Visible Spectrum ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Lanthanide Halide ◽  
Trivalent Lanthanide

Abstract In recent years, significant progress has been made in the red and green perovskite quantum dots (PQDs) based light-emitting devices. However, a scarcity of blue-emitting devices that are extremely efficient precludes their research and development for optoelectronic applications. Taking advantage of tunable bandgaps of PQDs over the entire visible spectrum, herein we tune optical properties of CSPbBr3 by mixing Nd3+ trivalent lanthanide halide cations for blue light-emitting devices. The CsPbBr3 PQDs doped with Nd3+ trivalent lanthanide halide cations emitted strong photoemission from green into the blue region. By adjusting their doping concentration, a tunable wavelength from (515 nm) to (450 nm) was achieved with FWHM from (37.83 nm) to (16.6 nm). We simultaneously observed PL linewidth broadening thermal quenching of PL and the blue shift of the optical bandgap from temperature-dependent PL studies. The Nd3+ cations into CsPbBr3 PQDs more efficiently reduced non-radiative recombination. As a result of the efficient removal of defects from PQDs, the photoluminescence quantum yield (PLQY) has been significantly increased to 91% in the blue-emitting region. Significantly, Nd3+ PQDs exhibit excellent long-term stability against the external environment, including water, temperature, and ultraviolet light irradiation. Moreover, we successfully transformed Nd3+ doped PQDs into highly fluorescent nanocomposites. Incorporating these findings, we fabricate and test a stable blue light-emitting LED with EL emission at (462 nm), (475 nm), and successfully produce white light emission from Nd3+ doped nanocomposites with a CIE at (0.32, 0.34), respectively. The findings imply that low-cost Nd3+ doped perovskites may be attractive as light converters in LCDs with a broad color gamut.

scholarly journals White Light Emission: A Full Vacuum Approach for the Fabrication of Hybrid White-Light-Emitting Thin Films and Wide-Range In Situ Tunable Luminescent Microcavities (Advanced Optical Materials 7/2016)

2016 ◽  
Vol 4 (7) ◽  
pp. 1134-1134
Author(s):  
Youssef Oulad-Zian ◽  
Juan Ramon Sanchez-Valencia ◽  
Manuel Oliva ◽  
Julian Parra-Barranco ◽  
Maria Alcaire ◽  
...  
Keyword(s):  
Thin Films ◽  
White Light ◽  
Optical Materials ◽  
Light Emission ◽  
White Light Emission ◽  
Light Emitting ◽  
Wide Range

scholarly journals Ultra-thin van der Waals crystals as semiconductor quantum wells

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Johanna Zultak ◽  
Samuel J. Magorrian ◽  
Maciej Koperski ◽  
Alistair Garner ◽  
Matthew J. Hamer ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emission ◽  
Van Der Waals ◽  
Emission Spectra ◽  
High Electron Mobility Transistors ◽  
Light Sources ◽  
High Electron ◽  
Light Emitting Devices ◽  
Precise Control ◽  
Electron Mobility Transistors

AbstractControl over the quantization of electrons in quantum wells is at the heart of the functioning of modern advanced electronics; high electron mobility transistors, semiconductor and Capasso terahertz lasers, and many others. However, this avenue has not been explored in the case of 2D materials. Here we apply this concept to van der Waals heterostructures using the thickness of exfoliated crystals to control the quantum well dimensions in few-layer semiconductor InSe. This approach realizes precise control over the energy of the subbands and their uniformity guarantees extremely high quality electronic transport in these systems. Using tunnelling and light emitting devices, we reveal the full subband structure by studying resonance features in the tunnelling current, photoabsorption and light emission spectra. In the future, these systems could enable development of elementary blocks for atomically thin infrared and THz light sources based on intersubband optical transitions in few-layer van der Waals materials.

Optical studies of Poly[p-(2,5-didodecylphenylene)ethynylene] in Thin Films

2006 ◽  
Vol 937 ◽  
Author(s):  
Lynn Rozanski ◽  
David A. Vanden Bout ◽  
Uwe H.F. Bunz
Keyword(s):  
Thin Films ◽  
Light Emission ◽  
Emission Spectra ◽  
Green Emission ◽  
Blue Shift ◽  
Polymer Chains ◽  
Emission Characteristic ◽  
Brick Wall ◽  
Interchain Interaction ◽  
Polymer Backbone

ABSTRACTUnlike many other conjugated polymers popular for use in LEDs, poly[p-(2,5-didodecylphenylene)ethynylene] (DPPE), shows less interchain interaction between polymer chains after annealing to an ordered film. Evidence of this decreased interchain interaction can be seen in the emission spectra of pristine and annealed films. Thin films of pristine DPPE show a broad featureless green emission, characteristic of an excimer-like state, whereas annealed films blue-shift and become structured, resembling dilute solution emission. DPPE packs into ordered domains after annealing, shown by birefringence, polarization anisotropy NSOM, and x-ray crystallography data. The lack of chromophore interaction in the ordered domains can be explained through a brick-wall-type packing motif, where the polymer backbone is insulated by the side chains of offset neighboring polymers. Electroluminescence spectra of pristine and annealed LEDs are nearly identical, both having green emission, unlike their different photoluminescence spectra. This is evidence that light emission in LEDs comes only from excimer sites within the film, which would indicate a decreased performance for the annealed devices compared to pristine devices. Preliminary data of pristine and annealed LEDs supports this theory, with most pristine devices having a slightly higher electroluminescence intensity compared to annealed devices.

Structure Analyses and Electrical Properties of Er-Doped ZnO Thin Films

2006 ◽  
Vol 301 ◽  
pp. 71-74 ◽  
Author(s):  
Shigeru Tanaka ◽  
Yukari Ishikawa ◽  
Dai Nezaki ◽  
Mitsuhiro Okamoto ◽  
Noriyoshi Shibata
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Light Emission ◽  
Infrared Light ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Linear Behavior ◽  
Doped Zno ◽  
Er Doped

Er-doped ZnO thin films which emitted intense infrared light in the vicinity of 1.5 μm were investigated from points of view of the microstructure and electrical properties. The result of X-ray diffraction (XRD) pattern revealed that the crystal lattice of ZnO was apparently expanded by doping of Er ions. Electrical resistance in the direction of thickness of Er-doped ZnO film showed linear behavior, which was resemble to that of undoped ZnO film. Infrared light emission phenomenon of the film was related to the chemical / physical state of Er ions in ZnO matrix.

Emissivity Of Coated Silicon At Elevated Temperatures

1998 ◽  
Vol 525 ◽  
Author(s):  
H. Rogne ◽  
H. Ahmed
Keyword(s):  
Optical Constants ◽  
Elevated Temperatures ◽  
Emission Spectra ◽  
Infrared Emission ◽  
Optical Measurements ◽  
Theoretical Modelling ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Electron Beam Heating

ABSTRACTIsothermal electron beam heating has been combined with in situ optical measurements in order to measure the emissivity of coated silicon samples at elevated temperatures. The coatings include a number of oxide, nitride, and silicon films. Infrared emission spectra were recorded from I to 9 μm for temperatures between 750 and 1200°C. The experimental results were compared with calculated theoretical values, which were predicted from the theory of thin film coatings, using a matrix model incorporating the optical constants for the materials. A good match between experimental and theoretical values validates the use of the infrared optical constants for theoretical modelling related to control and temperature measurements in rapid thermal processing systems.

Leakage current of Al- or Nb-doped Ba0.5Sr0.5TiO3 thin films by rf magnetron sputtering

1998 ◽  
Vol 13 (4) ◽  
pp. 990-994 ◽  
Author(s):  
Tae-Gyoung In ◽  
Sunggi Baik ◽  
Sangsub Kim
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Elevated Temperatures ◽  
Rf Magnetron Sputtering ◽  
Bst Thin Films ◽  
Bst Thin Film

The effects of Al and Nb doping on the leakage current behaviors were studied for the Ba0.5Sr0.5TiO3 (BST) thin films deposited on Pt/Ti/SiO2/Si(100) substrate by rf magnetron sputtering. Al and Nb were selected as acceptor and donor dopants, respectively, because they have been known to replace Ti-sites of the BST perovskite. The BST thin films prepared in situ at elevated temperatures showed relatively high leakage current density and low breakdown voltage. However, the BST thin films deposited at room temperature and annealed subsequently in air showed improved electrical properties. In particular, the leakage current density of the Al-doped BST thin film was measured to be around 10−8 A/cm2 at 125 kV/cm, which is much lower than those of the undoped or Nb-doped thin films. The results suggest that the Schottky barriers at grain boundaries in the film interior could determine the leakage behavior in the BST thin films.

Blue like Diamond Light Emitting Devices to be Massproduced

1989 ◽  
Vol 162 ◽  
Author(s):  
M. Kadono ◽  
S. Hayashi ◽  
N. Hirose ◽  
K. Itoh ◽  
T. Inushima ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Device ◽  
Electronic Devices ◽  
Chemical Properties ◽  
Wide Band ◽  
Wide Band Gap ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Device Applications ◽  
Diamond Thin Films

Recently, there has been considerable interest in electronic device applications of diamond thin films. The chemical properties of diamond is stable. So diamond thin films become very useful if they are used for electronic devices. We consider diamond thin films as blue like emitting devices because diamond has a wide band gap(about 5.5eV). Some light emitting devices have been known [1]. First of all we have been trying to deposit diamond thin films on the large areas. If they deposit on the large areas, light emitting devices may be massproduced.

Sign in / Sign up

Export Citation Format

Share Document