Development of large-area imaging arrays using epitaxially grown thick single crystal CdTe layers on Si substrates

Optimization of CdTe crystal growth and detector array fabrication techniques was studied to achieve large-area x-ray spectroscopic imaging arrays. The p-CdTe/n-CdTe/n⁺-Si heterojunction diode-type detector arrays were fabricated by using epitaxially grown thick single crystal CdTe layers on n⁺-Si substrates, were pixels were patterned by making deep vertical cuts on p-CdTe side using a diamond blade saw. The 2D (8×8) array developed exhibited very uniform response. We further demonstrated possibility of making larger arrays by fabricating (18×18) array using a 25 mm × 25 mm size single crystal and uniform CdTe epilayer grown on Si substrate.