Low-energy cathodoluminescence microscopy for the characterization of nanostructures

Abstract

Spatially and spectrally resolved low-energy cathodoluminescence (CL) microscopy was applied to the characterization of nanostructures. CL has the advantage of revealing not only the presence of luminescence centers but also their spatial distribution. The use of electrons as an excitation source allows a direct comparison with other electron-beam techniques. Thus, CL is a powerful method to correlate luminescence with the sample structure and to clarify the origin of the luminescence. However, caution is needed in the quantitative analysis of CL measurements. In this review, the advantages of cathodoluminescence for qualitative analysis and disadvantages for quantitative analysis are presented on the example of nanostructures.

Blue and green emissions with high color purity from nanocrystalline Ca2Gd8Si6O26:Ln (Ln = Tm or Er) phosphors

“…In recent years, solid-state lighting using light emitting diodes (LEDs) and flat panel technologies such the field emission display (FED) have attracted worldwide attention because of their important benefits including energy saving, safety, reliability, maintenance and environmentally friendly characteristics [1][2][3][4]. Although the phosphor selection for fluorescent lamps, LEDs and FEDs has been made long ago there is still considerable research activity to improve the chemical stability and to adopt the materials to the production technology for the respective applications [3][4][5][6].…”

“…Although the phosphor selection for fluorescent lamps, LEDs and FEDs has been made long ago there is still considerable research activity to improve the chemical stability and to adopt the materials to the production technology for the respective applications [3][4][5][6]. Luminescent materials with very high stability, which is invariable to operating conditions, is required for ongoing miniaturization, working lifetime improvement and spectral stability of fluorescent lamps on the one hand and brightness/contrast improvement in imaging systems on the other hand.…”

Veritable electronic characteristics in ZnO nanowire circuits uncovered by the four-terminal method at a low temperature

“…23,24 In addition, a red-shift of the exciton emission to lower energy is observed as the temperature increases as illustrated in Figure 2c, which could be attributed to the lattice thermal expansion and electron-phonon interaction. 25 The bandgap energy thus can be determined by the Varshni's empirical relation, 26 E g (0K)=3.36 eV, which could be assigned to neutral-donor-bound-exciton recombination in ZnO materials. 27 All the evidences suggest a high-quality crystal structure of the final ZnO products, allowing a following exploration on their intrinsic electronic properties.…”

Cathodoluminescence Microscopy of nanostructures on glass substrates

“…CL detection is in general performed from above the sample using a parabolic mirror that contains a small hole for the passage of the electron beam [9][10][11][12]. However, this limits the amount of generated signal that can be detected, because most of the light will be emitted into the higher refractive index, usually the sample substrate.…”