Improved PECVD processed hydrogenated germanium films through temperature induced densification

Infrared analysis of catalytic CO2 reduction in hydrogenated germanium

“…This observation and the underlying mechanisms are discussed in more detail elsewhere. 28 After the initial etching of the porous top region, the Ge–H vibrations gradually decreased with respect to the Ge–O vibrations, and after 25 hours only a fraction of the film thickness remained. It can be observed that the oxidation of the porous a-Ge:H film with n @600nm = 4.63 occurs at a much higher rate.…”

“…The HSM is seen to increase with respect to the LSM for decreasing n @600nm , which has been reported in earlier work. 28 Compared to hydrogenated silicon alloys, 38,39 HSM vibrations are the result of hydrogen bonded to germanium at the surfaces of nanosized voids. A shift of the peak position towards higher wavenumbers, as observed in a-Ge:H-5 with reference to a-Ge:H-3 and a-Ge:H-4, indicates that the vibrating Ge–H bonds reside at the surfaces of yet larger nanosized voids.…”

Opto‐Electrical Properties of Group IV Alloys: The Inherent Challenges of Processing Hydrogenated Germanium

“…The method for obtaining this metric, as well as examples of representative FTIR and Raman measurements, are reported elsewhere. [22] The thickness, real part of the refractive index at a wavelength of 600nm (n @600nm ) and optical bandgap energies were determined through spectroscopic ellipsometry (SE). The SE measurements were fitted using a Cody-Lorentz model.…”

“…The decrease of E 04 in this range is predominantly the result of variations in the crystalline phase fractions, as discussed in more detail elsewhere. [22] The right processing conditions, reported in Table 1, yield dense and stable a/nc-Ge:H films. Additionally, it can be observed that the 𝜎 d generally decreases with decreasing P RF and increasing T S .…”

“…In this section, the high level relations between the structural and opto-electrical characteristics are addressed. For the films presented in Figure 2 more information about the relation between the processing conditions and structural characteristics, as well as more detailed structural investigation of the films, is provided for GeCSn, [20] Ge, [22,[24][25][26] SiGe, [22,27] SiO. [24] From these collective works, three structural characteristics through which a change in density can be realized.…”