Durable infrared optical coatings based on pulsed DC-sputtering of hydrogenated amorphous carbon (a-C:H)

Abstract

Optical properties of low-temperature pulsed DC-sputter deposited ( ≤ 70 ° C ) hydrogenated carbon are presented. Increasing hydrogen incorporation into the sputter deposited carbon significantly decreases infrared optical absorption due to a decrease in deep absorptive states associated with dangling bonds. Hydrogen flow is optimized (hydrogen flow 3 sccm), achieving the best compromise between increased infrared transmittance and hardness for durable coating performance. Optical, environmental, and durability performance of pulsed DC-sputtered carbon incorporated in multilayer (a-C:H/Ge) infrared antireflective coatings indicates suitability as a durable infrared optical coating for commonly used infrared substrates, including temperature sensitive chalcogenide glass.

Pulsed DC sputter deposited hydrogenated carbon: an alternative durable infrared optical thin film material

“…The optical and mechanical properties of carbon thin films, such as hardness, transmittance, and stress level, can be precisely controlled by adding hydrogen to the films using the pulsed DC sputtering method. The degree of control that is offered supports specialized applications and unique solutions, such as gas detection and thermal imaging [4,5]. The pulsed DC sputtering method is preferable over traditional Plasma Enhanced Chemical Vapour Deposition (PECVD) methods, as PECVD methods having limited throughput and require high temperature deposition inhibiting the use for high throughput applications [6] and the use of temperature sensitive substrates [7].…”

Investigation and Band Gap Analysis of Pulsed Dc Magnetron Sputtered Diamond‐Like Carbon to Enhance Contact‐Electrification and Durability of Triboelectric Nanogenerators

“…However, the use of hydrocarbon-based feedstock can negatively impact the TENG durability as the presence of hydrogen passivates the free electron dangling bonds and in turn density, hardness, Young's modulus, and compressive stress of the deposited carbon films. [33] In our previous study, we optimized the use of a pulsed DC-sputtered magnetron deposition system where hydrogen-free DLC films were deposited without the use of either a hydrocarbon or a hydrogenated feedstock. [33][34][35][36] In TENG devices, a friction layer is typically composed of two materials with different electron affinities that are in contact with each other.…”

“…[33] In our previous study, we optimized the use of a pulsed DC-sputtered magnetron deposition system where hydrogen-free DLC films were deposited without the use of either a hydrocarbon or a hydrogenated feedstock. [33][34][35][36] In TENG devices, a friction layer is typically composed of two materials with different electron affinities that are in contact with each other. [37] When the two materials rub against each other, electrons transfer from one material to the other, creating a potential difference between the materials.…”

“…[ 33 ] In our previous study, we optimized the use of a pulsed DC‐sputtered magnetron deposition system where hydrogen‐free DLC films were deposited without the use of either a hydrocarbon or a hydrogenated feedstock. [ 33–36 ]…”

Thermal Conductivity Enhancement in Ion-Irradiated Hydrogenated Amorphous Carbon Films

“…Hydrogenated amorphous carbon (a-C:H) is a solid solution of carbon and hydrogen bonded together in an isotropic, amorphous network . Films of a-C:H are of interest for several industrial applications including friction coatings, − biomedical coatings, and optical and microelectromechanical devices, among others, due to their high hardness, inert chemical behavior, , wide band gap, and unique optical properties. , Differences in the properties of these films arise from variation in carbon bonding, allowing for “tunability” of the films for different applications. For example, higher degrees of tetrahedral carbon–carbon sp 3 bonding yield a more diamond-like behavior than films with a greater degree of hydrogen-terminated bonds. , …”