Analysis of lead oxide (PbO) layers for direct conversion X-ray detection

Abstract

Lead oxide (PbO) is a candidate direct conversion material for medical X-ray applications. We produced various samples and detectors with thick PbO layers. X-ray performance data such as dark current, charge generation yield and temporal behavior were evaluated on small samples. The influence of the metal contacts was studied in detail. We also covered large a-Si thin-film transistor (TFT)-plates with PbO. Imaging results from a large detector with an active area of 18 cm × 20 cm are presented. The detector has 960 × 1080 pixels with a pixel pitch of 184 ?m. The modulation transfer function at the Nyquist frequency of 2.72 linepairs/mm is 50%. Finally, a full size X-ray image is presented

Origin of n- and p-type conductivity in undoped α-PbO: role of defects

“…The tetragonal lead oxide α-PbO is characterized by a layered structure and appears in polycrystalline form upon compound growth [1]. The weak orbital overlap of the 6s 2 lone pairs of Pb atoms projected out from each layer holds the PbO layers together [11,12], while only 6p 2 valence electrons participate in formation of the hetero-polar bonds with oxygen atoms [12].…”

Исследование Механических, Электронных И Колебательных Свойств Оксидов Свинца Из Первых Принципов

“…Эти оксиды представляют значительный интерес, поскольку демонстрируют фотоактивность в широком диапазоне длин волн электромагнитных излучений, ис-пользуются в производстве красок, керамики, силикат-ных стекол, а также пористых наклеенных электро-дов в свинцово-кислотных аккумуляторах. Поликристал-лический оксид свинца является одним из наиболее перспективных материалов для использования в ка-честве фоторезисторов, преобразователя и детекторов рентгеновского излучения [1], компонентов защиты от гамма-излучения [2], а также различных стекол [3,4]. Ди-оксид свинца широко применяется в электрохимической промышленности и рассматривается как превосходный электрод [5] благодаря его низкой цене по сравне-нию с благородными металлами, высокой химической стабильности и каталитической активности в процессе выделения кислорода.…”

Spectral analysis of fundamental signal and noise performances in photoconductors for mammography

“…[14][15][16][17]21 However, a-Se suffers from low x-ray sensitivity due to a high effective ionization energy or w-value ($45 eV) and much research effort is being invested in the development of alternatives. Several candidate compound photoconductive materials have been identified, 17,[22][23][24][25][26][27] although limitations imposed by electrical properties, such as mean drift length, leakage current, material stability, reproducibility, and largearea availability hamper their development. [27][28][29] Optimal image quality can be achieved only when the DQE is as close to unity as possible.…”