Nuclear Instruments and Methods in Physics Research A 583 (2007) 125–130 Towards UV imaging sensors based on single-crystal diamond chips for spectroscopic applications A. De Sio a,Ã , A. Bocci a , P. Bruno c , R. Di Benedetto c , V. Greco c , G. Gullotta c , M. Marinelli b , E. Pace a , D. Rubulotta c , S. Scuderi c , G. Verona-Rinati b a Department of Astronomy and Space Science, University of Firenze, Largo E. Fermi 2, 50125 Firenze, Italy b INFN—Department of Mechanical Engineering, University of Roma ‘‘Tor Vergata’’, Italy c INAF—Astrophysical Observatory of Catania, Italy Available online 30 August 2007 Abstract The recent improvements achieved in the Homoepitaxial Chemical Vapour Deposition technique have led to the production of high- quality detector-grade single-crystal diamonds. Diamond-based detectors have shown excellent performances in UV and X-ray detection, paving the way for applications of diamond technology to the fields of space astronomy and high-energy photon detection in harsh environments or against strong visible light emission. These applications are possible due to diamond’s unique properties such as its chemical inertness and visible blindness, respectively. Actually, the development of linear array detectors represents the main issue for a full exploitation of diamond detectors. Linear arrays are a first step to study bi-dimensional sensors. Such devices allow one to face the problems related to pixel miniaturisation and of signal read-out from many channels. Immediate applications would be in spectroscopy, where such arrays are preferred. This paper reports on the development of imaging detectors made by our groups, starting from the material growth and characterisation, through the design, fabrication and packaging of 2  n pixel arrays, to their electro-optical characterisation in terms of UV sensitivity, uniformity of the response and to the development of an electronic circuit suitable to read-out very low photocurrent signals. The detector and its electronic read-out were then tested using a 2  5 pixel array based on a single-crystal diamond. The results will be discussed in the framework of the development of an imager device for X–UV astronomy applications in space missions. r 2007 Elsevier B.V. All rights reserved. PACS: 72.40.+W; 81.05.Dz; 85.60.Gz; 95.55.Rg Keywords: Diamond properties and application; MIS; UV detector 1. Introduction The use of synthetic single-crystal (SC) diamond films in the fabrication of electronic devices is solving most of the limitations related to polycrystalline diamond sensors. The absence of grain boundaries and a lesser internal stress than the polycrystalline material have improved the electronic performance of synthetic diamond [1–3]. Thus, using such a material in radiation and particle detector technology has led to high sensitivity and fast responses [4–7]. The synthesis of SC diamond is still improving and the results that have been achieved let foresee the adoption of diamond detectors in many research and industrial applications. The present study is aimed to solve the problems related to the miniaturisation of the pixels and the designing of a suitable read-out electronics. The reduction of the pixel size, for instance, is presently limited by the short scale non-uniformity of the diamond samples. Such anisotropies, in single-crystal diamond, are related to spatially localised defects, such as crystal twins or mesa structures, which are generated during the growth pro- cesses. The influence of these crystal defects on the ARTICLE IN PRESS www.elsevier.com/locate/nima 0168-9002/$ - see front matter r 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2007.08.188 Ã Corresponding author. Tel.: +39 055 2307615; fax: +39 055 2307622. E-mail address: desio@arcetri.astro.it (A. De Sio).