Shih Chun-Jen, Lin Chao-Yang, Chen Kai, Amin Nurul Ridho Al, Luo Dian, Hsu I-Sheng, Akbar Abdul Khalik, Biring Sajal, Lu Chih-Hsuan, Chen Bo-Han, Yang Shang-Da, Lee Jiun-Haw, Liu Shun-Wei
Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
Organic Electronics Research Center and Department of Electronic Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan.
Adv Sci (Weinh). 2023 Nov;10(31):e2302631. doi: 10.1002/advs.202302631. Epub 2023 Sep 22.
The intractable brittleness and opacity of the crystalline semiconductor restrict the prospect of developing low-cost imaging systems. Here, infrared visualization technologies are established with large-area, semi-transparent organic upconversion devices that bring high-resolution invisible images into sight without photolithography. To exploit all photoinduced charge carriers, a monolithic device structure is proposed built on the infrared-selective, single-component charge generation layer of chloroaluminum phthalocyanine (ClAlPc) coupled to two visible light-emitting layers manipulated with unipolar charges. Transient pump-probe spectroscopy reveals that the ClAlPc-based device exhibits an efficient charge dissociation process under forward bias. This process is indicated by the prompt and strong features of electroabsorption screening. Furthermore, by imposing the electric field, the ultrafast excited state dynamic suggests a prolonged charge carrier lifetime from the ClAlPc, which facilitates the charge utilization for upconversion luminance. For the first time, >30% of the infrared photons are utilized without photomultiplication strategies owing to the trivial spectrum overlap between ClAlPc and the emitter. In addition, the device can broadcast the acoustic signal by synchronizing the device frequency with the light source, which enables to operate it in dual audio-visual mode. The work demonstrates the potential of upconversion devices for affordable infrared imaging in wearable electronics.
晶体半导体难以解决的脆性和不透明性限制了低成本成像系统的发展前景。在此，利用大面积半透明有机上转换器件建立了红外可视化技术，该技术无需光刻就能呈现高分辨率的不可见图像。为了利用所有光生电荷载流子，提出了一种单片器件结构，该结构基于酞菁氯铝（ClAlPc）的红外选择性单组分电荷产生层，并与两个由单极电荷操纵的可见光发射层耦合。瞬态泵浦-探测光谱表明，基于ClAlPc的器件在正向偏压下表现出高效的电荷解离过程。这一过程由电吸收筛选的快速且强烈的特征表明。此外，通过施加电场，超快激发态动力学表明来自ClAlPc的电荷载流子寿命延长，这有利于电荷用于上转换发光。由于ClAlPc与发射体之间的光谱重叠微不足道，首次在没有光倍增策略的情况下利用了超过30%的红外光子。此外，该器件可以通过使器件频率与光源同步来广播声学信号，从而能够以双视听模式运行。这项工作展示了上转换器件在可穿戴电子产品中实现经济实惠的红外成像的潜力。
