High Efficiency Detectors for Photon Counting and Large FPA Applications (SAT)

The ultraviolet region of the spectrum is an area of space astrophysics where major discoveries can be made possible in the near future by significant yet feasible gains from technology. Combined improvements in detector quantum efficiency (5-10x), optical coatings and higher-performance wide-field spectrometers (5-10x), lead to increased multiplex advantage (10-100x). Single photon counting as well as large numbers of pixels are crucial. Figure 1 shows by simulation, an example of how a high QE photon-counting UV detector array with a large number of pixels makes a dramatic impact on discovery and science return in future missions. Recently, through APRA and JPL internal funding, we completed an aggressive and highly successful technology demonstration of high quantum efficiency (QE), solid-state, UV photoncounting arrays by applying JPLs back illumination processes including thinning, delta doping technology, and developing advanced antireflection (AR) coatings to commercially available Electron Multiplied Charge-Coupled Devices (EMCCDs). Using molecular beam epitaxy (MBE) and atomic layer deposition (ALD) to achieve atomic-scale control over the surface, JPLs technology is unique in producing silicon detectors with exceptional stability and worldrecord QE (greater than 50%) throughout the ultraviolet (UV). We propose to build on this success and the success of our past accomplishments in demonstrating and developing, high sensitivity, stable, and uniform UV/optical silicon imagers. The results shown in figure 2 and described in this proposal represent a breakthrough in single photon counting UV detector response. We propose to advance the maturity of this Solid state Photon counting Ultraviolet Detector (SPUD) and advance the manufacturability, and reliability of SPUD and other high efficiency silicon imagers which will have a strong impact on future instruments capability and future discoveries. By leveraging the investments in technology development and infrastructure for producing delta doped silicon detectors including the more recent acquisitions at JPL of production-scale MBE and ALD, we propose to create a routine and reliable source for production of high efficiency and innovative UV/Optical detector arrays for the community. In addition to advancing the TRL of the SPUD, this detector shown in figure 2 represents an example of the power of the technology proposed here. The QE and response stability can be applied to various silicon imager architectures that are called for in the next generation of instruments and applications. The proposed effort is in direct response for the needs of future NASA missions including the Astro2010 Decadal Survey recommendations for a 4- meter UV/optical telescope and UV detector and coatings technologies and this SAT call for Detectors and UV coatings. Furthermore, because of the dramatic efficiency increase in the detector, Hubble Class science will be possible with smaller size apertures. This effort is likely to have a great impact on future Probe- and Explorer-class missions.