비정질 실리콘/텔루륨 이종접합 기반 유연한 근적외선 광검출기에 관한 연구

다국어 초록 (Multilingual Abstract)

Flexible near-infrared (NIR) photodetectors are essential for next- generation wearable and deformable optoelectronic systems. In this work, we demonstrate a flexible heterojunction photodiode based on tellurium (Te) and n-type hydrogenated amorphous silicon (n-a-Si:H). By optimizing the phosphine (PH3) dilution ratio, the P25% condition yielded a compact amorphous network with reduced structural disorder and improved charge transport properties, enabling distinct diode rectification and suppressed leakage current. Furthermore, a highly phosphorus-doped front-surface-field (FSF) layer was introduced between the transparent conductive oxide and the n-a-Si:H layer to reinforce the internal electric field and suppress interfacial recombination. As a result, the optimized FSF device (P71.4%) achieved ~5.1 fold enhancement in responsivity and ~2.6 fold improvement in detectivity at 1050 nm, which was confirmed to originate from more efficient charge separation and extraction as supported by EQE analysis. In addition, the device retained over 90% of its initial responsivity after more than 4000 bending cycles at a 5 mm radius, demonstrating excellent mechanical durability. This study presents an effective design strategy for high-performance flexible NIR photodetectors through defect suppression and field engineering in low- temperature amorphous silicon heterostructures, highlighting strong potential for wearable biomedical sensing, optical communication, and flexible imaging applications.

목차 (Table of Contents)

• I. 서론 9
• II. 이론적 배경 11
• 2.1 텔루륨(Tellurium, Te) 개요 11
• 2.1.1 텔루륨의 구조적 특성 11
• 2.1.2 텔루륨의 광전자적 특성 12
• 2.2 수소화 비정질 실리콘(a-Si:H) 개요 13
• 2.2.1 a-Si:H 의 구조 및 결함 13
• 2.2.2 a-Si:H 의 도핑 15
• 2.3 포토디텍터 17
• 2.3.1 포토디텍터 원리 및 구조 17
• 2.3.2 이종접합(heterojunction) 포토다이오드 19
• III. 실험 방법 21
• 3.1 Te/n-a-Si:H 포토디텍터 제작 21
• 3.2 박막 및 소자 분석 23
• IV. 결과 및 고찰 24
• 4.1 n-a-Si:H 박막 분석 24
• 4.2 Te 박막 분석 31
• 4.3 n-a-Si:H/Te 이종접합 소자 제작 및 분석 34
• 4.4 FSF 박막 분석 및 소자 분석 40
• 4.5 소자 기계적 유연석 테스트 48
• V. 결론 50
• 참고문헌 51