Novel light absorbing species for a wavelength-selective high-temperature superconducting bolometer.

摘要

Wavelength-selective optical and near-infrared detectors have been created using various molecular materials coupled to bolometer structures fashioned from the high temperature superconductor YBa2Cu 3O7-delta. The molecular layer functions as an antenna, absorbing specific wavelengths of light and efficiently transferring this energy to the underlying superconductor. Initial sensors of this type featured layers of sublimed dyes as the antenna species; in this work, other alternative materials were developed, expanding functionality and increasing detection into the near-infrared. Several of these materials afforded switchable wavelength selectivity to the hybrid devices. Appropriate chemical methodologies were developed in each case in order to deposit the material in a manner which was compatible with the superconductor.;In this dissertation, several examples of applications in which wavelength discrimination in both the visible and infrared region are a critical aspect are discussed. Commercially available detectors for the visible and the near-infrared regions are compared and contrasted with the high temperature superconductor bolometer. Next, color-specific sensors are described in which selected dyes are dispersed in a polymer matrix. The polymer was chosen based upon considerations of chemical compatibility as well as reliable low-temperature adhesion to the superconductor. Using this matrix, a four color visible and near-infrared sensor is described with markedly improved wavelength selectivity compared to both the human eye and sensors constructed previously using sublimed dye overlayers. Next, lithographically patterned meandering path bolometers were created which showed greatly improved sensitivity. The construction of a 2 x 2 array of patterned microbridges wherein each microbridge functions as a separate color-specific sensor is also described.;The first switchable color specific high temperature superconductor detectors are then demonstrated. Here, conducting polymers were used to make sensors that were switchable with chemical and electrochemical redox methods, and photochromic dyes (dispersed in the above described polymer matrix) were developed as photoactive detectors that were switchable using ultraviolet light and heat. Finally, colloidal gold quantum particles were investigated as tunable light absorbing species. The particles were deposited on the superconductor using self assembly methods. As a result, energy transfer from quantum particles to the high temperature superconductor as been demonstrated for the first time.