Photovoltaic infrared sensor arrays in monolithic lead chalcogenides on silicon

Abstract

MBE growth of epitaxial IV-VI lead salt layers on Si (111) substrates and fabrication of photovoltaic infrared devices in the layers is reviewed. IV-Vi on Si IR sensors have potential as a low-cost technique of fabrication of large IR focal plane arrays for both t h e 3-5 pm and 8-12 pm ranges because of t h e easy fabrication procedure and because uniformity problems are much less severe in IV-VIS due to the weaker composition dependence of the bandgap compared with Cd, -,Hg,Te. Sensor arrays are fabricated in 2-4 pn thick PbTe. PbS, -,Se, and Pb, _.Eu,Se for 3 4 p m and in Pb,-,%,Se for 8-12 pm cut-off. An intermediate epitaxial stacked 0.2 pm thick CaF,BaF, bilayer serves for compatibility and helps to overcome the large lattice and thermal expansion mismatch between the Si substrate and the IV-VI layer. Perfectly smooth surfaces with surface defect concentrations down to 103cm-'. and x-ray rocking-curve linewidth of ~1 5 0 arcsec are obtained. Sensor arrays with 66 and 256 elements are described, the latter having been grown on standard Si chips with Ai metallization.

Ab initio study of cubic PbSxSe1−x alloys

“…These materials crystallizes in the rocksalt structure at ambient temperature and pressure. There are also many experimental studies for the mixture of these materials, for example, Lebedev and Sluchinskaya have found the appearance of ferroelectricity in these IV-VI semiconductors [23]; and investigated the samples of PbS x Se y Te 1−x−y quaternary solid solutions at low temperatures using electrical and X-ray methods [24]; photovoltaic infrared sensor arrays in monolithic lead chalcogenides on silicon are studied by Zogg et al [25]; the vacuum evaporated PbS 1−x Se x thin films were examined by Kumar et al, [26]; and multi-spectral PbS x Se 1−x photovoltaic infrared detectors [27] were realized by Schoolar et al The study of these type of alloys is very recent, and no theoretical ab initio calculation has been done to compare with. To further the insight in the nature of these materials we present here the results of ab initio total-energy calculations of the PbS and PbSe compounds and their ternary alloys PbS x Se 1−x in rocksalt structure.…”

Simulation Mechanical Properties of Lead Sulfur Selenium under Pressure

“…They has been largely used in infrared detectors, as infrared lasers in fiber optics, as thermoelectric materials, in solar energy panels, and in window coatings [2,3]. One of their interesting properties is their narrow fundamental energy band gap [4,5]; that is why, these IV-VI semiconductors are useful in optoelectronic devices such as lasers and detectors [6][7][8].…”

The effect of substrate bias voltage on PbTe films deposited by magnetron sputtering

“…For its use in any of the above applications, PbTe films are desirable. Various techniques have been developed for the preparation of PbTe films, including chemical vapor deposition [2], electrodeposition [3], molecular beam epitaxy [4,14], atomic layer deposition [5], hot-wall epitaxy [6], vacuum evaporation [7], magnetron sputtering [8], wet chemical synthesis [11] and so on.…”