Monolithic Integration of Semi-Transparent and Flexible Integrated Image Sensor Array with a-IGZO Thin-Film Transistors (TFTs) and p-i-n Hydrogenated Amorphous Silicon Photodiodes

Donghyeong Choi; Ji-Woo Seo; Jongwon Yoon; Seung Min Yu; Jung-Dae Kwon; Seoung-Ki Lee; Yonghun Kim

doi:10.3390/nano13212886

Monolithic Integration of Semi-Transparent and Flexible Integrated Image Sensor Array with a-IGZO Thin-Film Transistors (TFTs) and p-i-n Hydrogenated Amorphous Silicon Photodiodes

Nanomaterials (Basel). 2023 Oct 31;13(21):2886. doi: 10.3390/nano13212886.

Authors

Donghyeong Choi^{1

2}, Ji-Woo Seo^{1

2}, Jongwon Yoon¹, Seung Min Yu³, Jung-Dae Kwon¹, Seoung-Ki Lee², Yonghun Kim¹

Affiliations

¹ Department of Energy and Electronic Materials, Surface Nano Materials Division, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea.
² School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea.
³ Analytical Research Division, Korea Basic Science Institute, Jeonju 54907, Republic of Korea.

Abstract

A novel approach to fabricating a transparent and flexible one-transistor-one-diode (1T-1D) image sensor array on a flexible colorless polyimide (CPI) film substrate is successfully demonstrated with laser lift-off (LLO) techniques. Leveraging transparent indium tin oxide (ITO) electrodes and amorphous indium gallium zinc oxide (a-IGZO) channel-based thin-film transistor (TFT) backplanes, vertically stacked p-i-n hydrogenated amorphous silicon (a-Si:H) photodiodes (PDs) utilizing a low-temperature (<90 °C) deposition process are integrated with a densely packed 14 × 14 pixel array. The low-temperature-processed a-Si:H photodiodes show reasonable performance with responsivity and detectivity for 31.43 mA/W and 3.0 × 10¹⁰ Jones (biased at -1 V) at a wavelength of 470 nm, respectively. The good mechanical durability and robustness of the flexible image sensor arrays enable them to be attached to a curved surface with bending radii of 20, 15, 10, and 5 mm and 1000 bending cycles, respectively. These studies show the significant promise of utilizing highly flexible and rollable active-matrix technology for the purpose of dynamically sensing optical signals in spatial applications.

Keywords: a-IGZO; a-Si:H; flexible; image sensor; low-temperature process; oxide TFT; photodiode; transparent.

Grants and funding

This study was supported by the Fundamental Research Program (PNK9020) of the Korean Institute of Materials Science (KIMS) and the Technology Innovation Program (20022508, Development of Ultrahigh Temperature Activator and Core Process Technology for SiC Devices) of the Ministry of Trade, Industry, and Energy (MOTIE, Korea). This work was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT; Ministry of Science and Information Technology) (No. 2020M3H4A308182013). This study was supported by the Energy Technology Development Program of the Korean Institute of Energy Technology Evaluation and Planning (KETEP) (Grant No. RS-2023-00301944).