Fabrication of solar cell with CuInSe₂/high Ga/III ratio Cu(In,Ga)Se₂ absorber by sequential evaporation from ternary compounds

Abstract

Cu(In,Ga)Se2 thin films with high Ga content were fabricated by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds (CuGaSe2/(CuGaSe2+CuInSe2) = 0.8) for photovoltaic device applications. XRF analysis showed that the Cu:In:Ga:Se atomic ratio in all thin films was consistent with the amounts of the evaporating materials. The Ga/(In+Ga) mole ratio in the thin films was within the range from 0.61 to 0.88. XRD studies showed that the prepared thin films had a chalcopyrite Cu(In,Ga)Se2 structure. The best solar cell using Cu(In,Ga)Se2 thin film prepared at CuGaSe2/(CuGaSe2 + CuInSe2) = 0.8 demonstrated Voc = 496 mV, Isc = 27.57 mA/cm2, FF = 0.508 and efficiency = 6.95% without AR‐coating. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Study of Bandgap Energies of Cu(In,Ga)Se2 Thin Films Grown by a Sequential Evaporation Method Using Piezoelectric Photothermal Spectroscopy

“…The CIGS thin film samples were prepared by the sequential evaporation method as follows. 7,8) A Mo layer used as a back contact was prepared by radio frequency (RF) magnetron sputtering onto a soda-lime glass (SLG) substrate in Ar ambient. Before fabrication of CIGS thin films, the Mo/SLG substrate was heated in vacuum for 5 min at 500 C. After cooling down to 200 C, in the first step, a Cu-In-Ga-Se layer was evaporated from CuInSe 2 and CuGaSe 2 compounds onto the Mo/SLG substrate.…”

“…6) On the other hand, we proposed a new process using a vacuum deposition apparatus with three evaporation boats, which was the sequential evaporation technology from CuGaSe 2 and CuInSe 2 ternary compounds. 7,8) The proposed process has advantages of being able to easily control the Ga=ðGa þ InÞ mole ratio in CIGS thin films by changing the amount of CuGaSe 2 and CuInSe 2 evaporating materials in the first step. This enables us to obtain inexpensive equipment for preparation of the absorbing layer.…”

Preparation of Cu(In,Ga)(S,Se)2 thin films by sequential evaporation and annealing in sulfur atmosphere

“…Therefore, the Cu(In,Ga)(S,Se) 2 thin film with high Ga/(In+ Ga) ratio (around 0.8) is an important component for the tandem solar cell applications. We have proposed the process using a vacuum deposition apparatus with three evaporation boats, which was the sequential evaporation technology from CuGaSe 2 and CuInSe 2 ternary compounds [4,5]. Our proposed process has advantages to be able to easily control Ga/(In+ Ga) mole ratio in Cu(In,Ga)Se 2 thin films by changing the amount of CuGaSe 2 and CuInSe 2 evaporating materials in the first step and to use inexpensive equipment for preparation of the absorber layer.…”

Preparation of High Ga Content Cu(In,Ga)Se<sub>2</sub> Thin Films by Sequential Evaporation Process Added In<sub>2</sub>S<sub>3</sub>

“…On the other hand, a performance of Cu(In,Ga)Se 2 thin film solar cell with a Ga/(In+Ga) mole ratio of around 0.3 was improved by sulfurization of the film surface such as InS treatment by a wet process [5] and annealing in S vapor atmosphere [6]. We have proposed the process using a vacuum deposition apparatus with three evaporation boats which was the sequential evaporation technology from CuGaSe 2 and CuInSe 2 ternary compounds [7,8]. Our proposed process has advantages to be able to easily control a Ga/(In+Ga) mole ratio in Cu(In,Ga)Se 2 thin films by changing the amount of CuGaSe 2 and CuInSe 2 evaporating materials in the first step and to use inexpensive equipment for preparation of an absorber layer.…”