Response of chemical vapor deposition diamond detectors to X-ray

The outstanding properties of diamond, such as radiation hardness, high carrier mobility, high band gap and breakdown field, distinguish it as a good candidate for radiation detectors. The detectorʹs performance is strongly limited by the concentration of defects (grain boundaries and/or impurities) in chemical vapor deposition (CVD) diamond. We report the response of free-standing CVD diamond with a thickness of 300 μm and area of 2×2 cm2, synthesized by a hot filament chemical vapor deposition (HFCVD) technique, to 5.9 keV X-ray radiation from a 55Fe source. The linear I–V characteristics indicate that CVD diamond has good ohmic contacts. This detector also shows good results such as dark-current of 10−8 A, photocurrent of 10−6 A, energy resolution <0.4%, and a high ratio of signal to noise.