When a certain product is developed, such as a material, a device or a service and it results in the establishment of a specific field for such products with a large number of parties involved internationally, it is natural to compete to report the best product. Any fair competition requires rules to follow, which is not always the case when reporting the best products. As an example, when record efficiencies or lifetimes of a solar cell are reported in literature, a question is raised: “how have they been tested and evaluated?”. Often testing conditions for assessing product properties can have a significant impact on the product itself and solar cells are not an exception. Thus, when reports of record performances are appear, it leaves one wondering whether everyone is using the same conditions to assess device performance and whether the reports are comparable.
IEC (International Electrotechnical Commission), ASTM (American Society for Testing and Materials) and ISO (International Organization for Standardization) are organizations that can be turned to when faced with such questions. These organizations were specially established to develope guidelines and protocols for testing materials, products, systems and services. Many new fields including, for example, organic photovoltaics are lacking behind in terms of having international standards for product testing, while questionable high performance devices are being reported continuously. These fields are therefore faced with the challenge of creating such standards.
Inter-laboratory and round robin tests are the main tools for developing consensus standards for product testing. The basic idea behind these tools is sharing reference products among different parties and comparing the testing procedures and results, reaching a consensus on how to perform product testing in the best way. The diagram below presents the mechanisms of performing inter-laboratory and round robin tests. The advantage of the round robin approach is that the same product travels among all the sites and therefore allows direct comparison of results among the sites, while in the case of inter-laboratory studies each site is being compared only to the original product provider. The advantage of inter-laboratory studies is that it takes much less time to perform compared to round robin.
Fields like organic photovoltaics and many others need to continuously perform such studies in order to create a ground for establishing standards for product testing.
Suren A. Gevorgyan