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The purpose of this article is to analyze the efficiency of electricity generation in photovoltaic systems located on the building made on the basis of HIT-IBC cells for multi-family residential buildings. The comparative analysis of the efficiency of electricity generation by photovoltaic (PV) installations made of two cell types -Heterojunction with Intrinsic Thin-layer-Interdigitated Back Contact (HIT-IBC) and classical mono-crystalline silicon (mono-Si) - showed that the efficiency of HIT-IBC cells is 60% higher. These cells were selected for use as photo-voltaic systems located on the building to cover the demand for electricity through an exemplary multi-family residential building, consisting of 35 apartments divided into two, three and four-person households. Considering the previous calculations, in which it was shown that a PV installation made of HIT-IBC cells (PV1) is able to generate 192,75 kWh/(m2·y), annual electricity production was calculated by the indicated photovoltaic installation. It was found that the photovoltaic installation located on the roof of the building, based on HIT-IBC cells, will allow to cover the total electricity demand by a selected multi-family building. In addition, the installation’s payback period of 9 years was calculated, which takes a high place in the lifespan of photovoltaic installations of 20-25 years and thus ensuring the economic efficiency of the adopted technical solutions.

The article presents the results of investigations of the mechanisms of electric charge transfer in gallium arsenide subjected to poly-energic implantation with hydrogen ions, as a potential base material dedicated for photovoltaic applications. The main objective of the research was to determine the relationship between the temperature of isochronous postimplantation annealing and the probability of electron jumping between energy levels as a function of operating temperature and to test the possibility of creating additional intermediate energy levels in the semiconductor band gap by ion implantation, which in practice could allow increase in the efficiency of solar energy conversion in photovoltaic cells made on the basis of gallium arsenide modified by ion implantation technology. The conducted research allowed to identify two additional energy levels with activation energy values of 0.17 eV and 1.1 eV.

The aim of this article is to present the results of research aimed at confirmation whether it is possible to form an intermediate band in GaAs implantation with H + ions. The obtained results were discussed with particular emphasis on possible applications in the photovoltaic industry. As it is commonly known, the idea of intermediate band solar cells reveals considerable potential as the most fundamental principle of the next generation of semiconductors solar cells. In progress of the research, a series of GaAs samples were subjected to poly-energy implantation of H + ions, followed by high-temperature annealing. Tests were conducted using thermal admittance spectroscopy, under conditions of variable ambient temperature, measuring signal frequency in order to localize deep energy levels, introduced by ion implantation. Activation energy ∆E was determined for additional energy levels resulting from the implantation of H + ions. The method of determining the activation energy value is shown in Fig. 2 and the values read from it are σ 0 = 10 −9 (Ω•cm) −1 for 1000/T 0 = 3.75 K −1 and σ 1 = 1.34 × 10 −4 (Ω•cm) −1 for 1000/T 1 = 2.0 K −1 . As a result, we obtain ∆E ≈ 0.58 eV. It was possible to identify a single deep level in the sample of GaAs implanted with H + ions. Subsequently, its location in the band gap was determined by estimating the value of ∆E. However, in order to confirm whether the intermediate band was actually formed, it is necessary to perform further analyses. In particular, it is necessary to implement a new analytical model, which takes into consideration the phenomena associated with the thermally activated mechanisms of carrier transport as it was described in [13]. Moreover, the influence of certain parameters of ion implantation, post-implantation treatment and testing conditions should also be considered.

Cienkowarstwowe ogniwa fotowoltaiczne wykonane na bazie struktury CIGS (mieszaniny pierwiastków miedzi, indu, galu oraz selenu) należą do II generacji ogniw fotowoltaicznych. Wykazują one efektywność na poziomie zbliżonym do ogniw I generacji, lecz ze względu na niższe zużycie materiału, coraz częściej wypierają z rynku ogniwa krzemowe Artykuł przedstawia rezultaty badań dotyczą-cych sposobu otrzymywania warstwy buforowej CdS (siarczku kadmu), zastosowanej w cienkowarstwowych ogniwach fotowoltaicznych typu CIGS. Przyjęto dwa rozwiązania technologii nanoszenia: warstwa okna CdS uzyskana metodą rozpylenia magnetronowego oraz warstwa okna CdS uzyskana metodą kąpieli chemicznej (CBD-Chemical Bath Deposition). Struktura ta powinna posiadać odpowiednią wielkość przerwy energetycznej, która pozwali na większą absorpcję fotonów, a także wymaga się, aby była cienka (mniej niż 100 nm) i jednolita. Warstwy CdS zostały nałożone przez osadzanie w kąpieli chemicznej CBD na szklanych podłożach pokrytych Mo/CIGS (naniesione warstwy metodą sputteringu magnetronowego). Uzyskano dzięki temu warstwę emitera o grubości 80 nm po czasie osadzania 35 minut. Dla porównania warstwy CdS zostały nałożone poprzez sputtering magnetronowy na podłożu Mo/CIGS, uzyskanym tą samą metodą. Następnie oba rozwiązania zostały przebadane pod względem morfologii powierzchni na elektronowym mikroskopie skaningowym, jak również przeprowadzono analizy składu pierwiastkowego warstw. Zarówno jedna, jak i druga metoda prowadzi do otrzymania warstwy emitera CdS dla zastosowań w ogniwach CIGS.