Flexible Cu(In,Ga)Se₂solar cells fabricated using a polyimide-coated soda-lime glass substrate

Abstract

Flexible solar cells with a Cu(In,Ga)Se 2 (CIGS) absorber layer were fabricated on a polyimide thin film using a lift-off process. Polyimide-coated soda-lime glass (SLG) was used as a substrate for fabricating CIGS solar cells before the lift-off process conducted to make the cells flexible. A conversion efficiency of 13.4% was achieved by low temperature deposition; this value is comparable to that obtained by direct deposition on a rigid glass substrate even without an external Na source. The final conversion efficiency after the lift-off process was 12.7% with some area correction due to the partial peeling-off between CIGS and Mo. Open-circuit voltage and fill factor did not change before and after the lift-off process, suggesting that the lift-off process did not give any physical damage.

Efficiency enhancement of flexible Cu(In,Ga)Se2solar cells deposited on polyimide-coated soda lime glass substrate by alkali treatment

“…2,18,20) Our group already reported a fabrication method for flexible solar cells by depositing CIGS on PI-coated SLG and subsequently peeling off the PI layer from SLG. 21) By using this method, not only the thickness of PI can be reduced, but also the same fabrication method as that used for rigid substrates can be used, simplifying handling. It has been reported that CIGS thin films deposited on PI-coated SLG do contain Na, 22) but the quantity tends to be insufficient owing to the low substrate temperature of approximately 450 °C during deposition, which is the maximum temperature that the PI film can tolerate.…”

SiOxNy back-contact barriers for CZTSe thin-film solar cells

“…Furthermore, it cannot be excluded that a small amount of oxygen atoms from SiO x N y may diffuse into the CZTSe absorbers and lead to additional impurity states in the absorber, which could impact the defect landscape or influence the phase structure of kesterite material in relevant regions. Moreover, thicker SiO x N y diffusion barriers may further cause a harmful influence on the device performance by blocking sodium diffusion from SLG, which is generally considered to enhance the absorber quality in CIGS and kesterite solar cells [18][19][20]. However, based on our previous research, in which SiO x N y was investigated as barrier layers between SLG and Mo, a total blocking effect for sodium was only achieved with much thicker SiO x N y layers [21].…”

Flexible bifacial amorphous Si quintuple‐ and sextuple‐junction solar cells for Internet of Things devices

“…A similar peeledfilm method has already been used in CIGS. 17 At the time of peeling process, it was cut into a length of 10 cm and a width of 1.2 cm with a cutter. It has been confirmed that there is no change in solar cell characteristics before and after peeling process.…”