Photovoltaics International Papers

Because it leads to higher efficiencies than aluminium back-surface field (Al-BSF) cells, passivated emitter and rear cell (PERC) technology is attracting more and more attention in the industry and gaining market share. However, PERC technology brings new challenges with regard to the phenomenon of degradation: some monofacial/bifacial PERC cell modules were found to demonstrate much higher power degradation than Al-BSF cell modules after damp-heat (DH: 85°C and 85% relative humidity RH, 1000h) and potential-induced degradation (PID: 85°C and 85% RH, –1,500V, 96h) tests, which will be the focus of this paper.

The realistic measurement of solar cells is key for the whole PV industry, as accurate information about cell power is one of the most important aspects in solar cell purchase and PV module design.

Silicon heterojunction (SHJ) solar cell technology is an attractive technology for large-scale production of solar cells with a high conversion efficiency beyond 24%. One key element of SHJ solar cells, contrasting with today’s widespread passivated emitter and rear contact (PERC) cell technology, is the use of transparent conductive oxide (TCO), which poses challenges in performance and costs but also presents opportunities. This paper discusses these aspects and shows the potential for improving cell efficiency at reduced cost by using new TCOs deposited by direct current (DC) sputtering.

In this paper the situation of solar cell production in China is summarized, and an attempt is made to answer the question of whether passivated contacts could replace PERC technology, which will eventually reach its efficiency limit in the future.

Passivated-contact solar cell designs, such as TOPCon or silicon heterojunction solar cells (SHJs), enable cell efficiencies greater than 24%, and are promising candidates for the next revolution in mass production after the passivated emitter and rear cell (PERC). Plated metallization (Ni/Cu/Ag or Cu/Ag) fits well with new constraints on low-temperature processing and the combination of low material costs and highly conductive bifacial metal grids for these types of solar cell.

For the work reported in this paper, a new model of the screen-printing process was set up in order to improve the understanding of the screenprinting process, with a focus on the interaction between Ag paste and the screen.

Different types of PV backsheet provide modules with varying levels of protection in warm, humid conditions. Haidan Gong, Minge Gao and Yiwei of Wuxi Suntech’s PV test centre detail the results of research undertaken to better understand the properties of different backsheet materials in tropical conditions.

Half-cell modules are gaining an increasing market share because of their potential for increasing module power without requiring any changes to cell technology. However, it has emerged that different cell separation technologies can produce similar electrical performances of the half cells, yet lead to an entirely different mechanical behaviour of the cells.

The market share of bifacial solar modules is rising, because of the additional power yields of up to 20% per year, which reduce the levelized cost of electricity (LCOE). Many manufacturers have bifacial PV modules in their portfolios, with a majority of them employing bifacial passivated emitter and rear cell (PERC+) technology. In this paper, it is shown from the results of studies that rear-side-related potential-induced degradation (PID) effects can occur in addition to the conventional front-side shunting type (PID-s).

The recent trends in crystalline Si-based bifacial cell development are having a major impact on interconnection technology. This paper presents an overview of various bifacial interconnection technologies.