PbSe chalcogenide films are widely used as photosensitive elements in gas analysis devices. High absorption in the IR spectrum region and low electrical resistance are important characteristics. Continuous laser radiation exposure of films in the near UV range makes it possible to achieve the desired characteristics, replacing oven heat treatment in the technological process. In the considered laser technology, PbSe films are subjected to photothermal action by a spot of focused radiation in the progressive scanning mode. In this work, changes in the optical and electrical film properties were studied, and the mechanism of structural laser modification was also considered.

This paper shows the laser irradiation effect on optical characteristics on PbSe chalcogenide films as a result of irreversible structural modification. The features of film structure and property modification under the action of a continuous wave (CW) laser with a 405 nm wavelength and nanosecond laser pulses with a 1064 nm wavelength are studied. The valence and conduction bands boundaries displacement as a laser radiation result of photothermal action on the film until it darkens and bleaches, is demonstrated. Under CW near ultraviolet (NUV) laser action, the film was modified at a power density of 0.74 to 1.09 kW/cm². The near-infrared (NIR) laser pulses used ensured the film structure modification at a power density of 1.45 kW/cm² and a pulse duration of 4 to 20 ns. Scanning with a laser spot in these modes provides the desired change in the film’s optical characteristics, and this becomes a serious alternative to the technology of heat treatment in an oven.