Op-tection offers PL-based wafer inspection platform for efficiency forecast on as-cut wafers

Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on email

Op-tection has recently launched a new inspection platform based on Photo Luminescence technology. The PL inspection platform was developed in cooperation with Schott Solar Wafer, which bundles solid metrology experience in one hand with in depth process and material knowledge in the other hand. The result of this effort is the capability to quantify the achievable efficiency of solar wafers before they enter into the cell process line.


Solar cell makers sell their solar cells based on efficiency. Higher cell efficiency in general equals more money earned for the cell batch at hand. Wafer makers are often qualified and judged by cell makers based on the performance their wafers can deliver. Key point in both cases is that the wafer itself is often the limiting factor for achievable final solar cell efficiency. This applies in particular to polycrystalline as well as the new quasi-monocrystalline wafer type. A reliable forecast of the achievable efficiency that a wafer can achieve is important for both wafer and cell makers, as it will help wafer makers prove the value of their product to cell makers. Vice versa the cell maker is required to continuously increase process and production yield and required good wafer to be successful doing so.


To enable wafer and cell makers to achieve this goal, Op-tection offers PL-based sorting platform that automatically inspects and segregates wafers. The wafer under test is illuminated with strong laser light source to excite the luminescence response of the silicon. A sensitive and high-resolution camera combined with adapted filters records the PL image. This 2D image is a measure for the spatially resolved carrier lifetime of the silicon. Subsequent image processing and analysis of the various defects and structures, such as dislocations and material contaminations, is performed with proprietary algorithms that calculate metrics such as Edge contamination fractions, Dislocation clusters, PL intensity & distribution. Based on the calculated and individually marked wafer metrics, an efficiency forecast is made. Op-tection integrates this capability in sorters that allow segregation of wafers in multiple classes based on forecasted achievable efficiency. Sorters can be configured to handle various throughputs ranging from few hundred wafers per hour up to 1s capture time to meet current line cycle times. The wafer handling can be from stack-box to stack-box or from cassette to cassette or a combination of both to ensure a smooth handover to the next process step.


Op-tection's PL technology can be used for all types of solar wafers. The strongest benefit of this capability however applies to: Poly-Wafers: dislocation clusters, edge contamination fractions and corner brick metrics are weighted and used for a precise forecast.

Pseudo-Mono-Wafers: this new generation of wafer material has some distinct characteristics that require detailed investigation and efficiency forecasting. The very small amount of grain boundaries make this type of wafer look nearly like a single crystal from the outside. However, dislocations are present in this material, and unlike regular poly-wafers, there are just few grain boundaries. This can result in over-proportional growth/presence of dislocations in pseudo-mono material, which strongly impacts the achievable cell efficiency.


Op-tection Wafer-PL Sorter Series:   OSIS Wafer-PL-Sorter.


Currently available.

19 August 2021
The utility-scale PV market is poised for exponential growth and yet the industry still has many fundamental opportunities to improve on standards and best practice. Tracker shade loss has been one of those topics that deserve more attention, but has been typically handled by derate factors rather than trying to accurately forecast the loss over the life of the system. Join Nextracker’s subject matter experts, Aron Dobos and Neelesh Umachandran, and Rounak Kharait, director of solar energy assessments at DNV, for a webinar about why shade modeling matters and recommendations on what the solar industry should do about it.
25 August 2021
Energy Next is a new industry exhibition focusing on the latest renewable energy and energy efficiency technology, which will be held for the first time in 2021 in Sydney, Australia alongside the Clean Energy Council’s Australian Clean Energy Summit, the peak gathering of leaders driving Australia's energy transformation. Organised by the same people behind Australia’s largest clean energy event, All-Energy Australia, Energy Next will give visitors two days of access to key suppliers in the industry, free-to-attend professional development and industry workshops, and networking opportunities to better understand clean energy issues and solutions and learn about the latest developments in this transformational, dynamic sector.
25 August 2021
The Intersolar Summit Brasil Nordeste takes place in Fortaleza, Brazil. It addresses leading local and international experts on solar power and renewable energy in the region. The Summit’s mission is to provide in-depth education, enable high-quality networking opportunities, expand the use of PV technologies at regional and national level and strengthen the local PV industry. The Intersolar Summit Brasil Nordeste is organized by Intersolar South America - Latin America’s largest exhibition and conference for the solar industry: Solar Promotion International GmbH, Pforzheim, Freiburg Management and Marketing International GmbH (FMMI) and Aranda Eventos & Congressos Ltda, São Paulo as co-organizer.
25 August 2021
Join us to hear directly from the CTOs and heads-of-research from the top-20 cell/wafer producers to the PV industry today. The event will focus on predicting the key metrics underpinning the next big shift to n-type with answers to the key questions: When will the transition to n-type happen? Which companies will be first to 10 GW capacity and production? Who will be the key equipment suppliers for the new production lines? Which n-type process flow/architecture will emerge as the front-runner? What will polysilicon purity and wafer thickness levels look like for optimized n-type manufacturing? What will the upstream poly/wafer supply-chain look like in 5 years from now?
26 August 2021
In this webinar, JA Solar will present its product portfolio based on the latest technologies to improve your PV projects, ensuring maximum reliability and performance. During the webinar we will receive insight from JA Solar about its solar technology roadmap and how the manufacturer is providing customers with innovative solutions to suit their needs, while we will also analyse how to determine the best product solution for each solar project.
6 September 2021
The 38th European Photovoltaic Solar Energy Conference and Exhibition will be held online from 6 - 10 September 2021, allowing PV experts from all around the globe to participate with just one click! The EU PVSEC is the world's leading forum for PV Research and Development and the biggest Conference on PV Solar Energy worldwide. That is why PV experts from all around the globe are keen on gathering together each year to be part of this specialist’s event, to present and discuss the latest developments in Photovoltaics, to network and to conduct business.

Read Next

PV Tech Premium
July 30, 2021
Not only will solar be the dominant source of new power generation in Europe by 2025, cementing its position as the third largest market for solar globally, but the continent has placed the asset class at the very heart of its COVID-19 recovery strategy. As part of a week-long special report on PV Tech Premium, Liam Stoker, Edith Hancock and Jules Scully explore the drivers for solar in Europe, the key markets and the challenges that remain.
July 30, 2021
First Solar has unveiled plans to construct a 3.3GWdc module assembly facility in India, bolstering its manufacturing footprint outside of the US.
July 30, 2021
Anglo-Australian mining company BHP, in partnership with Canada’s TransAlta Renewables, is to build two solar farms and a battery storage system to help power its Mt Keith and Leinster nickel mines in Western Australia
July 30, 2021
German energy giant RWE has upgraded its earnings forecast for 2021 after “exceptionally positive” earnings trend
July 29, 2021
Tracker and racking provider Arctech has delivered SkySmart II tracking system to a 575MW agriculture-sharing solar project located in Nangong City, Hebei Province, China.
July 29, 2021
Unigreen Energy, owned by Hevel majority shareholder Ream Management LLC, has broken ground on a wafer and cell manufacturing plant that will produce 1.3GW of silicon n-type monocrystalline ingots and wafers as well as 1GW of heterojunction technology (HJT) solar cells.

Subscribe to Newsletter

Upcoming Events

Upcoming Webinars
August 19, 2021
At 9am (PT) | 6pm (CEST)
Solar Media Events
August 25, 2021
Solar Media Events
October 6, 2021
Solar Media Events
October 19, 2021