Experimental Testing of PV Module Performance

This study compares the manufacturer's technical data of several PV modules with real measured outdoor technical data. The irradiance effect on several PV modules is examined by the changing a tilt angle and comparing different meteorological situations of sky clearness (clouds) on the modules mounted outdoor and exposed to Sun. Also, the influence of temperature and dust on the performance of a PV panel is under research using measurement methods described in the paper. The measured current and voltage data at the clean surface of the PV module correspond to the declared data of the PV module manufacturer, and in the case of fouling of the module surface with dust, a power drop of 7.39% was measured.

Электронная структура термически окисленного вольфрама

Using the method of photoelectron spectroscopy, an in situ study in ultrahigh vacuum of the electronic structure of a clean surface of tungsten oxidized at an oxygen pressure of 1 Torr and temperature of 1000 K was carried out. The spectra of photoemission from the valence band and core levels O 1s, O 2s, W 4f under synchrotron excitation in the photon energy range 80  600 eV are studied. It was found that a semiconductor film of tungsten oxide is formed, which contains various tungsten oxides with an oxidation state of 6+ to 4+. On the surface, mainly tungsten oxides with an oxidation state of 6+ are formed, the proportion of which gradually decreases with distance from the surface with an increase in tungsten oxides with an oxidation state of 4+.

Identifying the origin of the Voc deficit of kesterite solar cells from the two grain growth mechanisms induced by Sn2+ and Sn4+ precursors in DMSO solution

The large Voc deficit of kesterite solar cell mainly comes from the defective surface caused by multi-phase fusion grain growth; direct phase transformation grain growth produces high quality absorber with clean surface and thus high device Voc.