Integration of Epitaxial IV–VI Pb-Chalcogenide on Group IV Vicinal Ge Substrate to Form p–n Heterogeneous Structures

Abstract

Integration of monocrystalline PbSe with vicinal Ge substrate is reported. The heterogeneous p−n junction structure combines the merits of both materials, with the potential to form a dual-band detector structure. The lattice constant and thermal expansion coefficient mismatch between PbSe and Ge typically prohibit the formation of a strong epitaxial interface, but its observation here is attributed to the enhanced surface kinetics influenced by the in situ surface treatment of the Ge substrate prior to PbSe deposition. The creation of a crack-free monocrystalline n-PbSe film on p-Ge substrate demonstrates a strong p−n heterojunction behavior with high rectifying factor and low reverse bias current density. Low X-ray diffraction (XRD) full width at half-maximum (FWHM) and strong photoluminescence (PL) indicate the formation of high-quality PbSe(100) films on industrystandard vicinal Ge(100) substrates, providing potential uses for photodetector and other heterojunction applications.

Sputtered SnTe Thin Films on Si and Ge as a Plasmonic Material

“…There are two key advantages in considering Ge as an alternative substrate over Si. First, single-crystal heteroepitaxial growth of IV–VI family semiconductors such as Pb 1– x Sn x Te and PbSe on Ge substrates has been reported. , Second, all Ge oxides can be thermally desorbed by heating to temperatures between 400 and 600 °C. − SnTe films were grown on Ge at varying growth temperatures: 20, 150, 250, and 300 °C. The native oxides of Ge were removed in situ by baking at 650 °C for an hour under high vacuum before deposition.…”

“…First, single-crystal heteroepitaxial growth of IV−VI family semiconductors such as Pb 1−x Sn x Te and PbSe on Ge substrates has been reported. 37,38 Second, all Ge oxides can be thermally desorbed by heating to temperatures between 400 and 600 °C. 39−44 SnTe films were grown on Ge at varying growth temperatures: 20, 150, 250, and 300 °C.…”

Theoretical design of uncooled mid-infrared PbSe P+pBn+ barrier detectors

“…This is attributed to the well-designed carrier transmission route in P + pBn + structure, which helps extract the photo-generated minority carriers, resulting in a lower dark current [58]. To build a P pBn + barrier detector, which is expected to enhance the overall quantum efficiency and detectivity of the uncooled detector, one would only need to integrate the pBn + structure in a heavily doped wide-bandgap P + -type Ge layer through mature MBE growth technology [42].…”

“…To further decrease the dark current of uncooled PbSe BIRD, in this paper, an improved P + pBn + barrier architecture is employed based on PbSe epitaxial growth on Ge wafers [42]. The performance of the uncooled PbSe P + pBn + barrier architecture is simulated by finite element analysis by establishing the relevant numerical model.…”

Design of uncooled mid-wave infrared detectors based on lead selenide barrier structure

“…25) Therefore, several PbSe-base heterojunction detectors were designed to achieve high-performance detection at RT, such as n-PbSe/p-Ge, n-CdSe (CdS)/p-PbSe type-II epitaxial or polycrystalline heterostructure photodiodes. [26][27][28] However, a lead-salt IR detector that takes advantage of the barrier structure and suppressed dark current has not been reported.…”