High efficiency CuIn1-xGaxSe2 (CIGS) thin film solar cells
CuIn1-xGaxSe2 (CIGS) thin film solar cells have been recognized as the most efficient thin-film solar cell, which is fabricated both on rigid substrate such as glass and on flexible substrate such as polyimide (PI). With these advantages such as low cost in fabrication of absorbing layer (thickness ~ 1.0-2.5 microns), light weight, high power density (up to 1100 W/kg in flexible cell), flexible CIGS, high performance for weak-light, long life and strong radiation resistance, CIGS solar cells exhibits the extensive application prospects as shown in Figure 1.
Kesterite Cu2ZnSnS4 (CZTS) thin film solar cells
Kesterite Cu2ZnSnS4 (CZTS) thin film solar cells have attracted considerable interests in the last decade and have shown potential to replace its well-developed predecessor Cu(In,Ga)Se2 solar cell with earth-abundant and environmentally friendly raw materials. The CZTS thin films in our study are fabricated by a two-stage process consisting of precursor deposition by co-sputtering and post-sulfuration treatment which is a suitable method for high volume manufacturing.
Flexible encapsulation thin film
In the conventional flexible encapsulation thin film, a thin compact inorganic Oxides and nitrides layer was usually used as the barrier layer. The soft polymer layers, sandwiched between two subsequent hard inorganic barrier layers, minimized the propagation of defects in the inorganic layer, which improved the barrier performance grammatically. However, the inorganic layers were too stiff to be used as stretchable encapusulation materials in the wearable electronic devices. Therefore we designed two novel encapsulation structures to solve this problem:
1.Based on the conventional multilayered structures, the functional layers were deposited on with a waved surface fabricated by micro-fabrication process, such as photolithographic process. This structure could convert the stretching stress into bending stress in the film which made it suitable for the encapsulation of the stretchable devices.
2.The Elastomer mixed with amount of two-dimensional nanofillers such as clay or graphene was used as the encapsulation materials. In this structure, the layered two-dimensional materials could lengthen the pathway for the gas permeants due to the increased tortuosity, which could still remain good barrier property even under stress.
