Thick and large area PIN diodes for the hard X-ray astronomy in the 10-60 k
eV range are developed. To cover this energy range in a room temperature an
d in a low background environment, Si PIN junction diodes of 2 mm in thickn
ess with 2.5 cm(2) in effective area were developed, and will be used in th
e bottom of the Phoswich Hard X-ray Detector (HXD), on-board the ASTRO-E sa
tellite. Problems related to a high purity Si and a thick depletion layer d
uring our development and performance of the PIN diodes are presented in de
tail. (C) 1999 Elsevier Science B.V. All rights reserved.