Potential‐induced degradation (PID) is a solar cell‐related degradation mechanism due to high potential difference in a photovoltaic (PV) module between the solar cells and its grounded frame. This type of degradation is well known for silicon PV; however, for perovskites it has not been thoroughly researched yet. Herein, the PID of perovskite solar cells is investigated for bias voltages of ±500 V, half of the currently used system voltage, and ±1000 V with regular I–V and electroluminescence measurements during the test. The devices show a high PID resistance under applied bias of ±500 V, far exceeding the recommended guidelines for silicon PV. However, for the bias voltage of –1000 V a rapid degradation is observed due to the ingress of sodium ions from the glass substrate as confirmed by the time‐of‐flight secondary ion mass spectrometry measurements of spatial and depth distribution of elements in solar cells. Positively biased devices show no degradation due to high voltage exposure. These results show promising signs that perovskite solar cells are PID proof for current PV system designs.

The influence of the flooding gas during ToF-SIMS depth profiling was studied to reduce the matrix effect and improve the quality of the depth profiles. The profiles were measured on three multilayered samples prepared by PVD. They were composed of metal, metal oxide, and alloy layers. Dual-beam depth profiling was performed with 1 keV Cs + and 1 keV O 2 + sputter beams and analyzed with a Bi + primary beam. The novelty of this work was the application of H 2 , C 2 H 2 , CO, and O 2 atmospheres during SIMS depth profiling. Negative cluster secondary ions, formed from sputtered metals/metal oxides and the flooding gases, were analyzed. A systematic comparison and evaluation of the ToF-SIMS depth profiles were performed regarding the matrix effect, ionization probability, chemical sensitivity, sputtering rate, and depth resolution. We found that depth profiling in the C 2 H 2 , CO, and O 2 atmospheres has some advantages over UHV depth profiling, but it still lacks some of the information needed for an unambiguous determination of multilayered structures. The ToF-SIMS depth profiles were significantly improved during H 2 flooding in terms of matrix-effect reduction. The structures of all the samples were clearly resolved while measuring the intensity of the M n H m – , M n O m – , M n O m H – , and M n – cluster secondary ions. A further decrease in the matrix effect was obtained by normalization of the measured signals. The use of H 2 is proposed for the depth profiling of metal/metal oxide multilayers and alloys.

Defluorination of polytetrafluoroethylene (PTFE) surface film is a suitable technique for tailoring its surface properties. The influence of discharge parameters on the surface chemistry was investigated systematically using radio-frequency inductively coupled H2 plasma sustained in the E- and H-modes at various powers, pressures and treatment times. The surface finish was probed by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The measurements of water contact angles (WCA) showed increased wettability of the pristine PTFE; however, they did not reveal remarkable modification in the surface chemistry of the samples treated at various discharge parameters. By contrast, the combination of XPS and ToF-SIMS, however, revealed important differences in the surface chemistry between the E- and H-modes. A well-expressed minimum in the fluorine to carbon ratio F/C as low as 0.2 was observed at the treatment time as short as 1 s when plasma was in the H-mode. More gradual surface chemistry was observed when plasma was in the E-mode, and the minimal achievable F/C ratio was about 0.6. The results were explained by the synergistic effects of hydrogen atoms and vacuum ultraviolet radiation.