An efficient Si light-emitting diode based on an n- ZnO/SiO₂–Si nanocrystals-SiO₂/p-Si heterostructure

Abstract

Si nanocrystals embedded in a SiO2 matrix and an n-type Al-doped ZnO (ZnO:Al) layer were applied to improve the external quantum efficiency from Si in n- ZnO/SiO2-Si nanocrystals-SiO2/p-Si heterojunction light-emitting diodes (LEDs). The Si nanocrystals were grown by low pressure chemical vapor deposition and the ZnO:Al layer was prepared by atomic layer deposition. The n-type ZnO:Al layer acts as an electron injection layer, a transparent conductive window, and an anti-reflection coating to increase the light extraction efficiency. Owing to the spatial confinement of carriers and surface passivation by the surrounding SiO2, the Si nanocrystals embedded in the SiO2 matrix lead to a significant enhancement of the light emission efficiency from Si. An external quantum efficiency up to 4.3 x 10(-4) at the wavelength corresponding to the indirect bandgap of Si was achieved at room temperature.

Properties of Silicon Dioxide Amorphous Nanopowder Produced by Pulsed Electron Beam Evaporation

“…Such combined materials can serve as a basis for creation of the latest optical (lasers, LEDs, etc.) and spintronic devices [16,17].…”

Structural and Optical properties of ZnO/PS nano composite before and after vacuum annealing treatment

“…ZnO has also gained much interest due to its advantages like good electrical, optical and piezoelectric behaviors, stability in hydrogen plasma atmosphere and low cost over other oxide thin films such as In 2 O 3 ,SnO 2 etc [7]. ZnO is a multifunctional semiconductor material that can be used in many applications such as antireflection coatings, window material for displays and sensors [9]. Therefore, Zinc oxide modified porous silicon (ZnO/PS) composite structures have attracted great interest due to its wide range of applications [1,[10][11][12][13].…”

Monodispersed ZnO Nanoparticles and Their Use in Heterojunction Solar Cell

“…Among them, zinc oxide (ZnO) is an important basic material from a versatile application point of view due to its large band gap (3.37 eV), low cost, and luminescent properties [4]. It is widely used in many fields, such as UV lasers [5], catalyst [6], gas sensors [7, 8], transparent conductive oxide [9], varistors [10], and light emitting diodes [11, 12]. …”