Transparent current spreading layers for optoelectronic devices

Abstract

In this paper we develop a simple model based on a leaky transmission line to assess the electrical performance of transparent current spreading layers for application to surface light emitting diodes.Figures of merit suitable for device design are obtained and these are applied to a range of material systems reported in the literature. These calculations show that materials with electrical characteristics approaching ultimate performance limits can be achieved. Furthermore, calculations of the electromagnetic absorption of conducting layers show that further improvements should be possible by selecting materials with the highest possible majority carrier mobilities, which enable films of greater thickness to be grown while maintaining high transparency, leading to very low spreading layer resistances. Ways of achieving improved mobility are also discussed.

Morphology control of fluorine-doped tin oxide thin films for enhanced light trapping

“…Transparent conductive oxides (TCOs) are a class of materials with a high electrical conductivity and high optical transparency, and have been widely implemented in many fields, such as light emitting diodes [1,2], solar cells [3], flat panel displays [4], low emissivity windows [5], and electrochromatic or smart windows [6,7]. Fluorinedoped tin oxide (FTO) is one of such materials and outperforms other TCOs due to its excellent properties of chemical inertness, thermal stability, and mechanical hardness and relatively low cost [8][9][10][11].…”

Optical absorption driven by dynamical symmetry breaking in indium oxide

“…Indium oxide (In 2 O 3 ) is a versatile wide band gap semiconductor [1] which finds applications in areas ranging from gas sensors [2] to optoelectronic devices such as solar cells or flat panel displays [3][4][5][6][7][8]. The optoelectronic applications arise mostly due to the use of tin-doped In 2 O 3 as an n-type transparent conductor, and a large body of research exists regarding both optical and transport properties of this material.…”

Influence of Preferred Orientation on the Electrical Conductivity of Fluorine-Doped Tin Oxide Films

“…Thin films made from transparent conducting oxides (TCOs) show high visible wavelength transparency and electrical conductivity at the same time, and have already been used in many devices requiring a transparent contact 1 . Typical examples include light emitting diodes 2 3 , solar cells 4 , flat panel displays 5 , low emissivity windows 6 , and electrochromatic, or smart, windows 7 8 . In addition, TCOs also offer an attractive prospect for completely transparent electronic display screens or even energy generation from photovoltaic cells invisibly incorporated into the windows of office buildings 9 .…”