Transparent heat mirrors for solar-energy applications

Abstract

Transparent heat-mirror films, which transmit solar radiation but reflect ir thermal radiation, have potentially important applications in solar/thermal/electric conversion, solar heating, solar photovoltaic conversion, and window insulation. We have used rf sputtering to prepare two types of films: TiO(2)/Ag/TiO(2) and Sn-doped In(2)O(3). To characterize the properties of heat-mirror films for solar-energy collection, we define the parameters alpha(eff), the effective solar absorptivity, and epsilon(eff), the effective ir emissivity. For our Sn-doped In(2)O(3) films, alpha(eff)/epsilon(eff) is comparable to the values of alpha/epsilon reported for the leading selective absorbers. Even higher values of alpha(eff)/epsilon(eff) are obtained for the TiO(2)/Ag/TiO(2) films.

Enhanced transmittance of ITO/Ag(Cr)/ITO (IAI) multi-layered thin films by high temperature annealing

“…The three major areas of applications of the TCO thin films are flat panel displays [1], solar cells [2][3][4], and energy efficient architectural glass coatings [5][6][7]. In general, these TCO materials served as a transparent conducting window for a large variety of electro-optical devices [1][2][3].…”

“…Therefore, a device compatible protective oxide cover is necessary which can enhance the electrical and optical performance of the metal based electrode in the form of multilayer structure. Such a metal-oxide based multilayers structure have been investigated previously with high visible transmittance and high infrared reflectance for the energy-efficient architectural applications, where the oxide layer also acted as a protective layer [5][6][7].…”

Conductive and semi-transparent Cu thin film fabricated using molecular precursor solutions

“…Infrared reflectance is useful in many fields such as optical, telecommunication, solar concentrator, and architectural applications [1], and metallic-copper thin films are one of the promising materials for these applications. Technologies for copper deposition of thin films having good quality include chemical vapor deposition, which requires careful reduction of copper precursors using hydrogen, and electroless plating.…”

Diamond-like carbon based low-emissive coatings

“…The purpose of the metal layer is to provide a high level of reflectance in the mid-IR while the dielectric layers act as anti-reflecting layers to increase the visible transmittance of the coating. Due to its lower absorptance in the visible region, Ag is most commonly used for the metal layer, however, Cu, Al, and Au can also be used [2]. For the dielectric layer, metal-oxides such as SnO 2 , ZnO, and TiO 2 are typically used [2][3][4][5].…”