2D free-standing Ge-doped ZnO: excellent electron-emitter and excitation-power-dependent photoluminescence redshift

Abstract

Ge-Doped ZnO 2D nanostructures show large current-emission capabilities (>35 mA cm−2) and an excitation power-dependent PL redshift.

Ge-doped ZnO nanowire arrays as cold field emitters with excellent performance

“…Nanowires are natural one-dimensional electron transport channels with morphologies, dimensions and electronic properties that are tunable via various approaches. Currently, many nanowires composed of various materials, including carbon materials [1][2][3][4], oxides [5][6][7][8][9][10], carbides [11][12][13], silicide [14][15][16] and so on, can be synthesized on a large scale and exhibit fantastic FE emission performances. The discovery of new types of cold cathode emission materials and improving their performances are important tasks.…”

Compositional and structural engineering of inorganic nanowires toward advanced properties and applications

“…Doping has appeared to be successful in improving the electron transport ability and reducing the work function of a nanowire by increasing the charge carrier concentration and simultaneously increasing the Femi level . Via doping, better figure‐of‐merit‐related parameters, such as the turn‐on/threshold electric field ( E to and E thr ) and maximum emission current ( I max ), were frequently reached in randomly distributed nanowires, such as SiC, WO 3‐ x , and ZnO, compared to their pure counterparts. Zhu's group synthesized vertically oriented well‐aligned In‐doped ZnO nanowires (Figure A‐C).…”

“…FET, field-effect transistor; NW, nanowire; HAADF, high-angle annular dark-field; SEM, scanning electron microscopy; STEM, scanning transmission electron microscopy result in improved FE performance via suppression of the screening effect of the electric field, thus increasing the field enhancement factor and the effective emission area. [67][68][69][70][71][72][73] However, among the numerous types of nanowires, there are a limited number intrinsically satisfying all the favorable factors, that is, low work function, high electron conductivity, Reproduced with permission. 78 Copyright 2011, American Chemical Society.…”

“…101 Bottom-up fabricated nanowires exhibit rich-tunable characteristics, such as defects, dopants, alloys, and heterostructures, via rational adjustment of the synthesis conditions, which then modulate the emission behavior. 37 Dopants and point defects in semiconductor nanowire crystals result in modification of the electronic structures by the generation of extra electronic levels, followed by tailoring of the emission spectrum if the defect levels participate in the radiative transition process, 33,70 which provides flexible design of nanowire light emitters. Pure ceramic Al 4 O 4 C crystal nanowires were reported as intense blue light emitters with a maximum emission wavelength at~418 nm that exhibit robust performance at various temperatures.…”

“…Benefiting from the facile growth of large‐scale (quasi‐) oriented NW arrays on planar substrates in a controllable manner (NW density, morphology, diameter, and length), diverse nanowires have been frequently investigated as field electron emitters in recent years, such as Si and silicide, B and boride, metal oxide, and carbide NWs . Rational design of the nanowire morphology and distribution can result in improved FE performance via suppression of the screening effect of the electric field, thus increasing the field enhancement factor and the effective emission area . However, among the numerous types of nanowires, there are a limited number intrinsically satisfying all the favorable factors, that is, low work function, high electron conductivity, outstanding thermal stability, and large field enhancement factor, which facilitate the achievement of a low turn‐on (threshold) electric field, large current emission, and stable long‐term emission.…”