物理化学学报 >> 2025, Vol. 41 >> Issue (1): 100007.doi: 10.3866/PKU.WHXB202311021

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倍增型全聚合物光电探测器及其在光电容积描记传感器上的应用

赵兴超1, 李晓明2, 刘明1, 赵子进1, 杨凯旋1, 刘蓬天1, 张皓岚1, 李金泰1, 马晓玲1, 姚琪3, 孙艳明2,*(), 张福俊1,*()   

  1. 1 北京交通大学, 发光与光信息教育部重点实验室, 北京 100044
    2 北京航空航天大学化学学院, 北京 100191
    3 京东方科技集团股份有限公司, 北京 100176
  • 收稿日期:2023-11-13 修回日期:2023-12-15 录用日期:2023-12-18 发布日期:2024-01-11
  • 通讯作者: Email: sunym@buaa.edu.cn (孙艳明)fjzhang@bjtu.edu.cn (张福俊)
  • 基金资助:
    中央高校基本科研业务费(2023YJS080); 北京市自然科学基金(4232073); 国家自然科学基金(U22A6002); 国家自然科学基金(62105017)

Photomultiplication-Type All-Polymer Photodetectors and Their Applications in Photoplethysmography Sensor

Xingchao Zhao1, Xiaoming Li2, Ming Liu1, Zijin Zhao1, Kaixuan Yang1, Pengtian Liu1, Haolan Zhang1, Jintai Li1, Xiaoling Ma1, Qi Yao3, Yanming Sun2,*(), Fujun Zhang1,*()   

  1. 1 Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing 100044, China
    2 School of Chemistry, Beihang University, Beijing 100191, China
    3 BOE Technology Group Co., LTD., Beijing 100176, China
  • Received:2023-11-13 Revised:2023-12-15 Accepted:2023-12-18 Published:2024-01-11
  • Contact: Email: sunym@buaa.edu.cn (Yanming Sun)fjzhang@bjtu.edu.cn (Fujun Zhang)
  • Supported by:
    the Fundamental Research Funds for the Central Universities of China(2023YJS080); Beijing Natural Science Foundation(4232073); National Natural Science Foundation of China(U22A6002); National Natural Science Foundation of China(62105017)

摘要:

我们以宽带隙聚合物聚(3-己基噻吩) (P3HT)为给体,窄带隙聚合物聚{2, 2'-((2Z, 2'Z)-((12, 13-双(2-癸基十四烷基)-6-(2-乙基己基)-4, 8-二甲基-6, 8, 12, 13-四氢-4氢-苯并[1, 2, 3]三唑并噻吩[2'', 3'': 4', 5']并吡咯[2', 3': 4, 5]并吡咯[3, 2-g]并噻吩[2', 3': 4, 5]并吡咯[3, 2-b]并[4, 5-e]吲哚-2, 10-二基)双(甲烷亚甲基))双(5, 5’-3-氧-2, 3-二氢-1氢-2, 1-二亚基茚))二丙二腈-连-2, 5-二噻吩} (PTz-PT)为受体,研制了基于氧化铟锡(ITO)/聚(3, 4-亚乙二氧基噻吩)-聚(苯乙烯磺酸) (PEDOT: PSS)/有源层/Al结构的倍增型全聚合物光电探测器(PM-APDs)。我们制备了P3HT : PTz-PT质量比为100 : 1、100 : 4、100 : 7和100 : 10的四种不同比例的二元PM-APDs。在黑暗条件下,由于Al的功函数和P3HT的最高已占据分子轨道(HOMO)之间存在0.8 eV的能级差距,空穴难以从铝电极注入到有源层中。有源层中的PTz-PT含量较低,缺乏连续的电子传输通道,导致有源层的电子传输能力较差。在光照条件下,由于有源层中PTz-PT含量较低,并且P3HT和PTz-PT的最低未占据分子轨道(LUMO)相差0.84 eV,光生电子会被孤立的PTz-PT捕获。Al电极附近的受陷电子会引起界面能带弯曲,实现空穴隧穿注入,从而导致外量子效率(EQE)值大于100%。在−8 V偏压下,基于P3HT : PTz-PT (100:4 wt/wt)的最优二元PM-APDs在300–1100 nm的光谱范围内具有超过100%的EQE。PM-APDs的EQE光谱形状取决于铝电极附近的受陷电子分布。通过引入聚合物聚(2-(4, 8-双(4-(2-乙基己基)环戊二烯并-1, 3-啶-1-基)苯并[1, 2-b: 4, 5-b']二噻吩-2-基)-5, 5-二氟-10-(5-(2-己基癸基)噻吩-2-基)-3, 7-二甲基-5H-4λ4, 5λ4-二吡咯[1, 2-c: 2', 1'-f][1, 3, 2]二氮杂硼嗪) (PMBBDT)作为第三组分,PM-APDs的EQE光谱形状变得更平坦。我们制备了P3HT : PMBBDT : PTz-PT质量比分别为90 : 10 : 4和80 : 20 : 4的三元PM-APDs。三元PM-APDs的EQE值在420–600 nm的范围内提高,而在630–870 nm的范围内降低。三元PM-APDs具有更平坦的EQE光谱是由于其在Al电极附近的受陷电子分布更均匀。此外,在连续光照和外加偏压的条件下,三元PM-APDs的稳定性高于最优二元PM-APDs。在−12 V偏压下,最优三元PM-APDs的EQE值在350 nm处为3500%,在550 nm处为1250%,在900 nm处为1500%。在−10 V偏压下,最优三元PM-APDs的比探测度(Dshot*)值在520 nm处为3.7 × 1012 Jones,在850 nm处为1.9 × 1013 Jones。最优三元PM-APDs在−10 V偏压下被白光连续照射170 min后,光电流为初始值的87%。我们利用最优三元PM-APDs搭建了光电容积描记(PPG)传感器并成功地测量了人体心率(HR),测得的HR与人体正常心率相符。

关键词: 光电倍增, 全聚合物光电探测器, 空穴隧穿注入, 受陷电子, PPG传感器

Abstract:

Photomultiplication-type all-polymer photodetectors (PM-APDs) based on structure of ITO/poly(3, 4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS)/active layer/Al were developed with wide bandgap polymer poly(3-hexylthiophene) (P3HT) as donor and narrow bandgap polymer poly{2, 2'-((2Z, 2'Z)-((12, 13-bis(2-decyltetradecyl)-6-(2-ethylhexyl)-4, 8-dimethyl-6, 8, 12, 13-tetrahydro-4H-thieno[2'', 3'': 4', 5']pyrrolo[2', 3': 4, 5]pyrrolo[3, 2-g]thieno[2', 3': 4, 5]pyrrolo[3, 2-b][1, 2, 3] triazolo[4, 5-e]indole-2, 10-diyl)bis(methaneylylidene))bis(5, 5'-3-oxo-2, 3-dihydro-1H-indene-2, 1-diylidene))dimalononitrile-alt-2, 5-dithiophene} (PTz-PT) as acceptor. A series of binary PM-APDs were prepared with P3HT : PTz-PT weight ratios of 100 : 1, 100 : 4, 100 : 7, and 100 : 10. In the dark, the holes are difficultly injected from Al electrode into the active layer due to the 0.8 eV injection barriers from the work function of Al onto the highest occupied molecular orbital (HOMO) level of P3HT. The limited PTz-PT content in the active layer results in the absence of continuous electron transport channel, leading to poor electron transport ability. The photogenerated electrons are trapped in isolated PTz-PT under light illumination due to the scarce PTz-PT content in active layer and 0.84 eV difference between the lowest unoccupied molecular orbital (LUMO) of P3HT and PTz-PT. The trapped electrons near the Al electrode induce interfacial band bending for hole tunneling injection, leading to external quantum efficiency (EQE) values exceeding 100%. The optimal binary PM-APDs based on P3HT : PTz-PT (100 : 4 wt/wt) exhibit a spectral response range from 300 to 1100 nm with EQE values over 100% at -8 V bias. The EQE spectral shape of PM-APDs is determined by the distribution of trapped electrons near the Al electrode. The shape of EQE spectra is further flattened by introducing polymer poly(2-(4, 8-bis(4-(2-ethylhexyl)cyclopenta-1, 3-dien-1-yl)benzo[1, 2-b: 4, 5-b']dithiophen-2-yl)-5, 5-difluoro-10-(5-(2-hexyldecyl)thiophen-2-yl)-3, 7-dimethyl-5H-4λ4, 5λ4-dipyrrolo[1, 2-c: 2', 1'-f][1, 3, 2]diazaborinine) (PMBBDT) as the third component. A series of ternary PM-APDs with P3HT : PMBBDT : PTz-PT weight ratios of 90 : 10 : 4 and 80 : 20 : 4 were prepared. The EQE values of ternary PM-APDs are increased in the range from 420 to 600 nm and decreased in the range from 630 to 870 nm. The flatter EQE spectra of ternary PM-APDs are derived from more uniform distribution of trapped electrons near the Al electrode. Furthermore, the ternary PM-APDs exhibit higher stability under continuous illumination and applied bias than the optimal binary PM-APDs. The optimal ternary PM-APDs exhibit EQE values of 3500% at 350 nm, 1250% at 550 nm and 1500% at 900 nm under −12 V bias, as well as specific detectivity (Dshot*) values of 3.7 × 1012 Jones at 520 nm and 1.9 × 1013 Jones at 850 nm under −10 V bias. After 170 min continuous white light illumination at −10 V bias, the optimal ternary PM-APDs possess photocurrent of 87% initial value. A photoplethysmography (PPG) sensor was successfully realized by employing the optimal ternary PM-APDs to measure human heart rate (HR), with the measured HR consistent with the normal value of human HR.

Key words: Photomultiplication, All-polymer photodetector, Hole tunneling injection, Trapped electrons, PPG sensor