Meyer Burger is a leading global technology company where discovering the unexplored, developing new technologies and improving tried and tested products and processes are the drivers of our customer-focused culture of innovation. Here you will find a selection of technical white papers which provide you in-depth insight into our solutions and technologies.

Cell and module design from the LCOE perspective

As the share of PV in the energy mix increases, it is logical to compare electricity generation by PV and other energy sources. A common method is to calculate the energy price by means of the levelized cost of electricity (LCOE): this allows different technologies to be compared on the basis of a standardized calculation, both within PV and with other sources of energy generation.

In this paper the PV-module-related technological criteria that have a positive impact on the LCOE calculation are derived. The sensitivities of these criteria are then examined, and the basis for the choice of wafer, cell and module technologies is established with a view to achieving the lowest LCOE values.

Highly flexible coating system for the PV industry

For many years plasma-enhanced chemical vapour deposition (PECVD) technology has been an indispensable part of PV development. In addition to the deposition of a PECVD silicon nitride layer as an anti-reflective coating (ARC) on the front of a solar cell, the passivation of the rear surface by PECVD for the passivated emitter and rear cell (PERC) concept is growing in popularity.

Roth&Rau’s multiple application inline MAiA platform was conceived for industrial-scale applications of this type as well as for R&D purposes, and is demonstrating outstanding results in these areas. Thanks to the modular design and process flexibility of the new MAiA 2.x machine generation, additional application areas are being opened up, such as plasma-based texturing of wafer surfaces and coating deposition for the manufacture of heterojunction (HJT) solar cells.

As well as for the amorphous silicon layers needed for this purpose, just a few nanometres thick, the new MAiA platform can also be used for transparent conductive oxide (TCO) coatings by means of a conversion to a physical vapour deposition (PVD) sputtering unit.

Reducing wire wear by mechanical optimization

Diamond wire is the main cost factor in wafer manufacturing: understanding the mechanisms limiting the wire lifetime is therefore of great economic importance.

In this paper, wire characterization methods are described and applied to investigate the wear of diamond wire. The insights obtained lead to the conclusion that two main wear patterns can be distinguished: the first is the necessary cutting wire wear (CWW) originating from the interaction of the wire with the material to be cut, and the second is the undesirable non-cutting wire wear (NCWW), primarily due to interaction of the wire with itself.

In an innovative new machine set-up, NCWW has been reduced to a minimum, resulting in an increase in diamond-wire cutting performance.

The Grid TOUCH contacting system

Since 2010, Meyer Burger's competence centre for measurement technologies, Pasan, has intensively studied the measurement uncertainties related to the assessment of the electrical performances of PV devices (modules and cells).

One of the targets is to spread this knowledge on the PV market in order to make PV stakeholders aware of the financial importance of these uncertainties. Pasan uses this know-how in its development projects. The goal is to reduce the measurement tools’ contributions to the measurement uncertainty.

GridTOUCH is a new cell contacting solution for the IV performance measurement of busbarless cells. This tool was developed using the uncertainty approach so as to obtain a measurement you can rely on.

Heterojunction Technology - The solar cell of the future

Wafer-based silicon photovoltaic (PV) production has only changed slightly in the last forty years. The standard concept comprises p-type silicon wafers, fired contacts and encapsulation.

Cost reduction is necessary if PV is to survive without feed-in tariffs and be competitive with grid electricity costs. Therefore levelised cost of electricity (LCOE) is one of the primary metrics for the cost of electricity produced by both utility scale and distributed power systems. The fastest path to lower LCOE is to introduce high efficiency solar cell concepts like the heterojunction technology (HJT). Photovoltaic systems using heterojunction technology (HJT) modules outperform any other PV systems and this paper will explain why.

Automation in PV Manufacturing

The ultimate goal of PV manufacturing is to produce the highest quality of solar cells at the lowest possible cost. Translated into manufacturing requirements, this means that throughput, equipment uptime and yield must be continuously increased in a manufacturing environment while improvements and subsequent generations of products are implemented in parallel.

Automation is a key element in understanding the relevant process behavior, monitoring and controlling the process windows, ensuring stable processes, achieving the necessary product quality at all times, guaranteeing error-free production and promptly detecting any anomalies. Collecting and evaluating all of the applicable data, and controlling equipment performance with a high degree of complexity, rank among the challenges of automation.

The general objective of automation is to move the right material at the right time to the right place and process it correctly – while controlling all of these steps in real time. The ability to do this in a reliable, predictable and flexible manner has a direct impact on factory performance.

In this paper, the main components of automation will be described, and some ROI examples will be discussed for a PV manufacturing line.

Technological developments in module production

In solar module manufacturing, three main processes can be distinguished: cell connection, lamination and testing/sorting. Each of these processes has a major impact on cell efficiency, solar module lifetime and module manufacturer turnover. It is therefore of the utmost importance that all the processes are correct, to get the most out of the cells and guarantee 20–30 years’ lifetime.

This paper describes novel technologies that are used in the module manufacturing process to ensure maximum module efficiency (electrical connection: Soft Touch and SmartWire Connection Technology) and lifetime (cross-linking density: non-disruptive X Link measuring method) as well as module manufacturer turnover (module testing: DragonBack® for high-capacitance solar technologies). All these technologies are ready for the highest efficiency c-Si cells (> 21% cell efficiency).

Meyer Burger‘s heterojunction cell technology

The price of crystalline silicon feedstock has fallen significantly, which means thin-film PV must struggle even harder to increase its market share. Since all the other costs of a PV installation, such as the material for module production and system mounting and the installation expense, are constant or rising, energy harvest per area must be increased through the introduction of affordable, high-efficiency solar cell technology.

Conventional PV solar cells using p-type multicrystalline or monocrystalline silicon wafers have already reached efficiency limits which cannot be exceeded by cheap improvements in production: a technology shift is therefore necessary.

In view of the high-efficiency PV solar cells that have already been commercialized, the most promising technology for mass production with a minimum number of process steps is the p-type a Si:H/n-type c-Si heterojunction cell pioneered by Sanyo’s heterojunction with intrinsic thin layer (HIT) technology. Testing of these cells requires longer pulse durations combined with uniformity and pulse stability. As throughput rates on cell lines continue to grow, a demand for measurement methods to support the higher speeds is created.

Effective quality sorting of crystalline wafers

Improvements in quality and efficiency as well as in cell-line yield rely on the in-line measurement of critical parameters. Physical metrics – such as cracks, chips and thickness – as well as electrical resistivity are common criteria for the sorting of under-performing wafers.

A new method of in-line photoluminescence (PL) imaging enables wafer performance to be assessed in an early production step by measuring crystal defects and impurities, which are key parameters in determining the achievable cell efficiency.