Electric and device properties of TiO2 layers as an electron selective contact in silicon solar cells
Changhyun Lee1, Soohyun Bae1, Hyunju Lee3, Yoonmook Kang2, Hae-Seok Lee1, Donghwan Kim1
1Korea University, Seoul, South Korea
/2KU-KIST Green School, Seoul, South Korea
/3Toyota Technological Institute, Nagoya, Japan

This study reports the characteristics about titanium oxide as a carrier selective layer when it applied at silicon solar cells. Especially, we compared titanium oxide layers which were fabricated using simple deposition methods by thermal evaporator and ALD.  Uniformity of the films were confirmed by using ellipsometer and HR-TEM, and the phase and chemical composition of the film were analyzed by XRD and XPS. Also, the passivation quality of each membrane was confirmed by measuring carrier lifetime using QSSPC. XPS and UPS analysis showed the band alignment and carrier selectivity of TiO2 layers according to the deposition method and the electrical properties of the films were confirmed by measuring the contact resistivity. We could confirm the chemical and field passivation quality according to the formation method of titanium oxide through this experiment and measurement. Also, we could understand device characteristics when metal oxides applied on silicon solar cells used as carrier selective layers.