Electroluminescence Devices Based on Si Quantum Dots/SiC Multilayers Embedded in PN Junction

Physica Status Solidi (a)

et al. 2016

Hydrogenated amorphous Si films were prepared by a plasma‐enhanced chemical vapor deposition technique. As‐deposited samples were then thermally annealed at various temperatures to obtain nanocrystalline silicon films. The microstructures and carrier‐transport characteristics were investigated during the transition process from amorphous to nanocrystalline phase. It was found that the Hall mobility was improved while the dark conductivity was increased by over two orders of magnitude after annealing. Temperature‐dependent Hall measurements were performed in the temperature range from 310 to 575 K. Hall mobility first increases with rising temperature to 400 K and then decreases with further increasing temperature. The different temperature dependence of Hall mobility shows that the microscopic mechanisms governing charge transport are different for nanocrystalline Si films in different temperature regions.

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Microstructure and carrier‐transport behaviors of nanocrystalline silicon thin films annealed at various temperatures

Physica Status Solidi (a)

et al. 2016

“…8 X. Xu et al used laser crystallization technique to get the p-i-n structures containing nc-Si:SiC films and they observed the improved electroluminescence due to the enhanced radiative recombination probability. 9 Usually, nc-Si:SiC films can be obtained by growing Si-rich SiC films or amorphous Si/SiC multilayers with subsequently thermal annealing at high temperature. [5][6][7][8][9][10][11][12] By controlling the Si/C ratio or the post-annealing conditions, the optical band gap can be tunable which brings convenience to the design of optoelectronic devices.…”

Section: Introductionmentioning

confidence: 99%

“…9 Usually, nc-Si:SiC films can be obtained by growing Si-rich SiC films or amorphous Si/SiC multilayers with subsequently thermal annealing at high temperature. [5][6][7][8][9][10][11][12] By controlling the Si/C ratio or the post-annealing conditions, the optical band gap can be tunable which brings convenience to the design of optoelectronic devices. However, the SiC matrix with a large band gap usually has a poor conductive property and in turn impedes the carrier transport process which will deteriorate the device performance.…”

Section: Introductionmentioning

confidence: 99%

Formation of high conductive nano-crystalline silicon embedded in amorphous silicon-carbide films with large optical band gap

Qian

et al. 2016

AIP Advances

High conductive phosphorus-doped nano-crystalline Si embedded in Silicon-Carbide (SiC) host matrix (nc-Si:SiC) films were obtained by thermally annealing doped amorphous Si-rich SiC materials. It was found that the room conductivity is increased significantly accompanying with the increase of doping concentrations as well as the enhanced crystallizations. The conductivity can be as high as 630 S/cm for samples with the optical band gap around 2.7 eV, while the carrier mobility is about 17.9 cm2/ V·s. Temperature-dependent conductivity and mobility measurements were performed which suggested that the carrier transport process is strongly affected by both the grain boundaries and the doping concentrations.

“…Silica-based semiconductor nanocrystals have attracted much interest in recent years due to their possible applications in many kinds of nanoelectronic and optoelectronic devices such as next generation of solar cells, nonvolatile memories, and single electron transistors [1][2][3][4][5]. Compared with Si, Ge has larger electron and hole mobility, which can be used to fabricate the Ge-based thin film transistor (TFT) and nonvolatile memories with good device performance [6,7].…”

Section: Introductionmentioning

confidence: 99%

Microscopic Understanding of the Carrier Transport Process in Ge Nanocrystals Films

Journal of Nanomaterials

Wang

Tang

et al. 2018

Hydrogenated amorphous germanium ( -Ge:H) films were prepared by a plasma enhanced chemical vapor deposition (PECVD) technique. Ge nanocrystals (Ge NCs) films were obtained by thermal annealing of the as-deposited samples at various temperatures. P-type behavior in Ge NCs films without any external doping was attributed to the holes accumulation caused by acceptor-like surface states. It can be found that the dark conductivity and Hall mobility reached as high as 25.6 S/cm and 182 cm 2 /V⋅s in the Ge NCs film annealed at 500 ∘ C, which were increased by over four and three orders of magnitude higher than that of the as-deposited film (1.3 × 10 −3 S/cm and 0.14 cm 2 /V⋅s, resp.). Carrier transport mechanisms of Ge NCs films association with the microstructural characteristics were investigated. Three kinds of temperature-dependent conductivity behaviors, which exhibit the linear relationships of ln versus −1/4 , −1/2 , and −1 , respectively, were observed in the temperature regions from 10 K to 500 K, showing different microscopic mechanisms governing carrier transport in Ge NCs film.