Infrared photoluminescence ‐ a tool for HgCdTe crystal research

Abstract

Material and structural parameters of narrow-gap p-type HgCdTe are investigated by infrared photoluminescence. The method is used for analyzing the energy gap, the carrier lifetime, and heterointerfaces and to monitor defects like inclusions. The spatial distribution of the quantities mentioned has been investigated by applying the mapping technique known for 111 -V semiconductors. The method is a powerful tool for both crystal growth and device manufacturing. Material-und Struktureigenschaften des schmalliickigen Halbleiters p-HgCdTe werden mittelsInfrarot-Photolumineszenz untersucht. Dabei werden die Breite der Energieliicke, die Tragerlebensdauer und Heterogrenzen untersucht sowie Einschliisse sichtbar gemacht. Durch Anwendung des von den I11 -V-Halbleitern her bekannten Abtastverfahrens kann die raumliche Verteilung der genannten GroDen sichtbar gemacht werden. Photolumineszenz kann als prozeDbegleitende Methode sowohl bei der Kristallziichtung als auch bei der Bauelementeentwicklung eingesetzt werden.

Photoluminescence in Mercury Cadmium Telluride – a Historical Perspective. Part I: 1966-1996

“…The idea of using PL as a tool for analyzing the value of the bandgap, the carrier lifetime, and the quality of heterointerfaces, as well as to monitor defects like inclusions in MCT was further developed by Tomm et al, when they investigated the optical properties of bulk MCT (grown by THM) and LPEgrown films [32]. The spatial distribution of the quantities mentioned above was investigated by applying the mapping technique that was well-known for III-V semiconductors.…”

“…Schmidt et al [33] described PL mapping of semiconductor MCT wafers, which was introduced by Tomm et al [32], in a few more details. The maps of integral luminescence were studied at different powers of the exciting laser.…”

A new model for the absorption coefficient of narrow-gap (Hg,Cd)Te that simultaneously considers band tails and band filling

“…When high excitation levels were required, a Q-switched Nd:YAG laser ('TFWHM=80 ns, where FWHM denotes the full width at half-maximum) was employed as an excitation source, spectral discrimination and detection were accomplished with a conventional double monochromator and a fast (Hg,Cd)Te photodiode; for details, see Ref. 17. (iv) Pumped absorption (PA): PA measurements were done with a pump and probe method.…”