Defect State Analysis in Ion‐Irradiated Amorphous‐Silicon Heterojunctions by HAXPES

Abstract

The efficiency in HIT (heterojunction with intrinsic thin film) solar cells strongly depends on the passivation of dangling bonds at the a‐Si:H/c‐Si interface by hydrogen, introduced during the plasma‐enhanced CVD process. Herein, controlled defects that are introduced by Ar ion irradiation have been studied. It has been observed by hard X‐ray photoemission spectroscopy (HAXPES) that during Ar ion implantation, Si–H bonds in the a‐Si:H layer are broken and become dangling bonds. The number of dangling bonds in the a‐Si:H layer has been quantified, and the electronic states associated to them have been identified, which explains previously observed photoluminescence transitions.

Interaction of VSe2 with Ambient Gases: Stability and Chemical Reactivity

“…To date, surface properties of VSe 2 have been only scarcely investigated. The presence of dangling bonds at the surface arising from the truncation of the crystal can influence the energetics of adsorption of reactants at sites located at the surface . Moreover, the presence of surface defects, specifically Se vacancies, has a key role in the determination of the chemical stability and, correspondingly, the catalytic properties .…”

Alternate stabilization methods for CZTSSe photovoltaic devices by thermal treatment, dark electric bias and illumination

“…This can be understood as post-production ordering and should mainly increase the initial power. The irradiance is assumed to mainly drive o-o or o-d transitions as weak bonds (shallow states or van-der-Waals bonds) may be broken by photons, as also found for amorphous silicon (a-Si) (Lee et al, 2019). Finally, the effects of electrical forward bias (current) in the dark were reportedly different for CIGS and CdTe technologies.…”

High-Resolution Photoemission Study of Neutron-Induced Defects in Amorphous Hydrogenated Silicon Devices

“…Our interpretation is confirmed by the observation that the high BE contribution gradually disappears as the sample is continuously sputtered (Figure S3). It is worth noting that the clear energy separation of the two peak groups is crucial to get separate information about the coating and the underneath films, even at the photon energy (1400 eV) used in this work when compared with High photon energy photoemission (HAXPES) measurements performed at 3, 5, 8 KeV [15]. To single out the a-Si:H film components, we performed a fit of the spectra by the KolXPD code [25].…”

“…The Si2p 3/2 components at 99.1 eV, 99.4 eV and 99.7 eV, in agreement with ref. [15], are assigned to the component labeled Dis Si related to the amorphous silicon (including a statistical distribution of bond lengths and dangling bonds), the crystalline c Si-Si and hydrogenated Si-H silicon, respectively. The deconvolution fit parameters are listed in the Supporting Information.…”

“…Nowadays, due to instrumental improvements, the spectroscopic fingerprint of the hydrogenation and the contribution of the different inequivalent Si atoms are easily distinguishable. Nevertheless, to the best of our knowledge, the only study in the literature which report a spectroscopic characterization of a-Si:H systems uses high resolution hard X-ray XPS in the 3, 5, 8 KeV ranges [15]. Here, we successfully characterize a-Si:H device prototypes by using high resolution XPS in the soft X photon energy with a twofold aim: define a protocol for XPS and XAS measurements in characterizing future real devices and get a deeper understanding of the damaging mechanism induced by irradiation.…”