Dear Harikesh,

Since the solar cells must work on diverse environment with varying temperature and humidity and other weather conditions they must be tested after encapsulation in solar modules where the cells will be sealed against the leak of air and moisture from reaching the cells.

As for the testing the solar cells during the fabrication and after the fabrication when they are encapsulated, one has to see for testing environment which will not detract the solar cells and fully preserve them fully operating.

As for the perovskite solar cells there is an optimum moisture conditions[1]

May be one of the most important test conditions is the scan rate which must be sufficiently slow to avoid formation of hysteresis. This condition can be experimentally determined by reducing the scan rate such that the forward and backward scan coincide almost with each others.

As for the test conditions for qualifying the solar cells they must be measured under standard test conditions of room temperature and pressure with SPECIFIC AIR MASS.

[1] https://ieeexplore.ieee.org/document/8362049

Best wishes

Hi Harikesh,

This is a very important topic in the field of halide perovskite optoelectronics due to the complicated, mixed ionic electronic, nature of conduction in these materials.

From the phrasing of your question it seems like you are already familar with some of the important details of the measurement.

Given that perovskites have mobile ionic species that respond to external biases, it is important to give ions time to equilibrate before recording a current measurement at a given bias, so slow scan rates are preferred. This is further complicated by the hysteretic nature of current-voltage scans in perovskite solar cells, that the short circuit-open circuit scan will be different to open circuit-short circuit scan, most likely due to differences in accumulation of ions at interfaces. (https://pubs.rsc.org/en/content/articlehtml/2014/ee/c4ee02465f ) So both directions of the scan should be reported. If your material has been light soaked beforehand, it is critical to report this and the exact conditions that it was performed in, particularly in relation to your question about the ambient conditions - different environmental conditions can cause different light soaking effects. ( Article Metal Halide Perovskite Polycrystalline Films Exhibiting Pro...

In reality, the best method to determine the performance is to measure the stabilised power output at the max power point. JV curves in perovskite devices require a lot of caveats to make claims about them. Stabilised power output does what it claims to do, no caveats required!

Kyle

Abdelhalim Zekry Kyle Frohna

It seems MPPT is the better way to go..But we rarely see good papers with proper MPPT measurements on perovskites..

Hi, Harikesh

The emerging PV, DSSC, PSC, ..., have the capacity effect and hysteresis effect. Therefore, I-V of the device show forward/backward can't overlap.

If you want to improve accuracy under I-V or IPCE measurement, some test method can refer from

https://www.researchgate.net/project/Performance-rating-measurement-of-emerging-PV-for-Outdoor-Solar-AM15G-and-Indoor-lighting/update/5a1ccc354cde267c3e6f269a

or

https://www.researchgate.net/project/Performance-rating-measurement-of-emerging-PV-for-Outdoor-Solar-AM15G-and-Indoor-lighting

Thank you.

Best wishes

Mickey

Hi, Harikesh

Energy harvesting for IoT (Internet of things) application presents a straightforward solution for easily powering those remote devices using clean energy. ​Therefore, the standard of the emerging PV applied in IoT follow

(A) For Outdoor (Solar) environment, we meet IEC 60904 series, SEMI PV57, SEMI PV69, SEMI PV76 and IEC 61215.

(B) For Indoor (Lighting) environment, we meet SEMI PV57, SEMI PV76 and SEMI PV80.

In addition, we developed the Indoor lighting simulator, meet SEMI PV80, for energy harvesting under Indoor (Lighting) environment for IoT applications.And our Lab get a ISO 17025 certified solar cell laboratory for Low lighting by TAF No.1340 ( https://www.taftw.org.tw/wSite/mp?mp=2 ). The more detail follow,

​(1) https://accreditation.taftw.org.tw/taf/public/basic/viewApplyItems.action?unitNo=1340 

(2) Reference to SEMI PV80 (indoor lighting simulator)/SEMI PV57 (I-V)/SEMI Doc 5980 (indoor-lighting STC)

(3) indoor-lighting STC ==> A/1000 lx/25 deg C ==> Defined on SEMI Doc 5980 and this test method was recently approved and will be published in early 2019.

(4) https://www.researchgate.net/profile/Mickey_Long2 

(5) https://www.researchgate.net/project/Performance-rating-measurement-of-emerging-PV-for-Outdoor-Solar-AM15G-and-Indoor-lighting​ 

Hope this is clear and we are happy to discuss this further if necessary.

If you have any further question/comments/suggestion, please feel free to contact me. 

Best regards,

Mickey.