Hiệu suất phát quang điện của các polyme dựa trên 1,1-bis(4-(N,N-dimethylamino)phenyl)-2,3,4,5-tetraphenylsilole trong ba kiến trúc catot

Science in China Series B: Chemistry - Tập 56 - Trang 1129-1136 - 2013
ZhiTian Liu1,2, SuJun Hu1, LinHua Zhang2, JunWu Chen1, JunBiao Peng1, Yong Cao1
1State Key Laboratory of Luminescent Materials & Devices, South China University of Technology, Guangzhou, China
2School of Materials Science & Engineering, Wuhan Institute of Technology, Wuhan, China

Tóm tắt

Một monome silole mới với hai nhóm thay thế 4-(N,N-dimethylamino)phenyl trên nguyên tử silic đã được thiết kế và tổng hợp. Sau đó, ba copolyme PF-N-HPS1, PF-N-HPS10 và PF-N-HPS20 được thu được thông qua quá trình đồng polymer hóa các dẫn xuất 2,7-fluorene với monome silole ở tỷ lệ cho ăn lần lượt là 1%, 10% và 20%. Các tính chất hấp thụ UV-vis, điện hóa, phát quang và phát quang điện (EL) của chúng đã được nghiên cứu. PF-N-HPS sở hữu mức năng lượng HOMO trong khoảng −5.25–−5.58 eV, và cho thấy phát xạ màu xanh lá cây. Sử dụng PF-N-HPS làm lớp phát xạ, ba đi-ốt phát quang polymer khác nhau đã được chế tạo, bao gồm thiết bị A với ITO/PEDOT/PF-N-HPS/Al, thiết bị B với ITO/PEDOT/PF-N-HPS/Ba/Al, và thiết bị C với ITO/PEDOT/PF-N-HPS/TPBI/Ba/Al. Với thiết bị A, PF-N-HPS chỉ cho thấy hiệu suất EL rất thấp từ 0.06–0.33 cd/A, cho thấy rằng catot Al không thể bơm electron vào hiệu quả từ các polyme phát xạ chứa các nhóm 4-(N,N-dimethylamino)phenyl. Đối với thiết bị B, barium có chức năng công việc thấp cung cấp việc bơm electron tốt hơn, và hiệu suất EL có thể được cải thiện lên 0.85–1.44 cd/A. TPBI với mức năng lượng HOMO sâu −6.2 eV có thể tăng cường khả năng vận chuyển electron và chặn lỗ. Do đó, các tái tổ hợp đã được điều chỉnh và hiệu suất EL được tăng cường đáng kể từ 4.56–7.96 cd/A cho thiết bị C. Việc tách lớp phát xạ và catot kim loại bằng lớp TPBI có thể cũng làm giảm sự tắt exciton tại giao diện catot.

Từ khóa

#silole #copolymer #electroluminescence #polymer light-emitting diodes #HOMO #electron injection #TPBI

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