| 학회 | 한국재료학회 |
| 학술대회 | 2018년 봄 (05/16 ~ 05/18, 삼척 쏠비치 호텔&리조트) |
| 권호 | 24권 1호 |
| 발표분야 | G. 나노/박막 재료 분과 |
| 제목 | Engineering the high-crystalline SnS and SnS2 thin films, and their FET characteristics |
| 초록 | Tin monosulfide (SnS) and tin disulfide (SnS2) have non-toxicity, low cost, and good optoelectronic properties due to their two-dimensional (2D) crystal structures. Recently, they are emerging as 2D semiconductor materials after appearances of graphene and black phosphorus. SnS2 is an n-type semiconductor and has hexagonal structure that individual layers consisting of three atomic planes, such as CdI2. It has been studied due to the same crystal structure and similar electrical characteristics with transition metal dichalcogenides (TMDCs). In the case of SnS, it has been studied as a strong candidate for solar cell absorber materials due to good optical properties. But recent studies of SnS are also focused on 2D layered structure due to its orthorhombic double layer structure. Additionally, SnS has a high challenging goals as a p-type 2D material. Though these characteristics, very few studies have been done to obtain high quality SnS and SnS2 thin films. In this presentation, we deposited high crystalline SnS thin films by atomic layer depositon (ALD). High crystalline SnS2 thin films were also obtained using phase transition of the SnS thin films by H2S ambient annealing. SnS thin films were deposited with tetrakis(dimethylamino)tin (Sn[N(CH3)2]4) and hydrogen sulfide (H2S) at 170 °C. Subsequently, H2S ambient annealing was performed using tube furnace at 450°C. Consequently, we could obtain remarkably high crystalline SnS and SnS2 thin films. After transition from SnS to SnS2, the optical bandgap increased from 1.35 to 2.70 eV, and absorption coefficient decreased from ~105 to ~104 cm-1 at visible region, respectively. Electrical band structure and switching device behaviors of p-type and n-type characteristics were also identified, and highly crystalline orthorhombic and hexagonal layer structures of SnS and SnS2 thin films were directly observed. The on-off current ratios of the SnS and SnS2 FETs were 8.8 and 2.1ⅹ103 and mobilities of 0.21 and 0.014 cm2/Vs. |
| 저자 | 최형수, 신석윤, 이주현, 박현우, 이남규, 정찬원, 조해원, 송석휘, 전형탁 |
| 소속 | 한양대 |
| 키워드 | two-dimensional materials; Atomic Layer Deposition (ALD); Phase transformation; Field effect transistors (FETs) |
