A new class of semiconducting materials called organic-inorganic halide perovskites hereafter could lead to commercial photoelectric devices due to the ultrahigh-performance and low cost. Meanwhile, perovskite-based photodetectors also have a rapid evolution in recent years. On the part of optical sensors, visible light detection is crucial for many applications, including imaging, medical treatment, industrial auto-control and so on. However, it is difficult for traditional preparation techniques to reach large-scale preparation accompanied by splendid performance of the device. Herein, we reported a method for high performance photodetctor by brush-coating. The device structure of the photodetector is ITO/PEDOT:PSS/CH3NH3PbI2.4Br0.6/PC61BM/C60/LiF/Ag, and the composite perovskites are consisting of CH3NH3PbI3 and CH3NH3PbBr3 with optimized mixing ratio which is crucial for not only enhancing the photon absorption but also ensuring a adjustable detection range .The device shows an excellent detectivity of ~1011 Jones under the illumination of 650 nm light at the bias of -0.5V. Due to the brush-coating process, the dark current is effectively suppressed down to 10-10 A. The present results suggest a promising strategy for fabricating outstanding perovskite-based photodetectors and provide a potential strategy for large-area fabrication.
A high performance organic integrated device (OID) has been realized with a thermally activated delayed fluorescence (TADF) material namely, 4,5-bis(carbazol-9-yl)-1,2-dicyanobenzene (2CzPN) and another transport material named 4,7-diphenyl-1, 10-Phenanthroline (Bphen) with an interbedded architecture as the active layer. The OID had a high detectivity of 0.8×1012 Jones at -1 V under the UV-365 nm illumination with an intensity of 0.2 mW/cm2, and yielded an exciplex EL light emission with a maximum luminance of ~12000 cd/m2. While the non-intebedded device has a detectivity of 4.1×1010 Jones and a maximum luminance of 8300 cd/m2.
We demonstrated ultraviolet organic photodetectors based on poly(N-vinylcarbazole) polymeric matrix (PVK) and phosphorescent material of bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2'] iridium(acetylacetonate) [(t-bt)2Ir(acac)] blend film. The structures are the indium-tin oxide (ITO)/PEDOT : PSS/PVK/Bphen/Ag and ITO/PEDOT : PSS/PVK : (t-bt)2Ir(acac) (1 : 10 %wt)/Bphen/Ag. Under UV light illumination, a high photocurrent density of 3.44 mA/cm2 at -4 V was obtained, which is 6.6 times higher than that of without (t-bt)2Ir(acac) material. The superior performances of the device doped with (t-bt)2Ir(acac) material resulted from the UV light absorption efficiency and triplet nature of the phosphorescent complex.
Charge carrier losses of organic solar cells (OSCs) based on Subphthalocyanine (SubPc)/C60 heterojunction have been
studied through the measurements of incident light intensity dependent response of the device. The light intensity was
varied between 0.03 and 100 mW/cm2. The results showed that short circuit current density follows a linear dependence
on light intensity (Pin), while open circuit voltage logarithmically increase with Pin with a slop of 120 mV/decade,
indicating that the charge carrier losses are governed by trap-assisted recombination through interface states between
donor and acceptor, with an estimated trap density of order 1024 m-3. Moreover, the inverse dependence of shunt
resistance (RPA) on light intensity reveals that charge carriers are trapped in the bulk of active layer as well as at the
organic/electrode interface, resulting in the decrease of fill factor (FF) with Pin.
Efficient organic photovoltaic cells based on a phosphor of (t-bt)2Ir(acac) were demonstrated. Also, the photovoltaic
performances of organic solar cells with a device structure of ITO/(t-bt)2Ir(acac):CuPc (doping rate R=0 and
0.25)/C60/BCP/Ag were determined based on the current density (J)-voltage (V) curves of a series of devices. The
absorption spectra of doping layer (t-bt)2Ir(acac):CuPc and C60 films on quart substrates were measured to gain a direct
insight of absorption ability of dopant (t-bt)2Ir(acac). Then, revised optical transfer matrix theory was adopted to study
inner effect of dopant (t-bt)2Ir(acac) on the enhanced device performance, which shows that (t-bt)2Ir(acac) dopant
increases the light density of doping layer by reorganizing the light distribution inside organic films. However, the light
absorption efficiency ηA of device with R=0.25 does not improve. According to the unchanging value of open circuit
voltage VOC and similar fill factor FF, the assumption that two devices with R=0 and 0.25 possess similar charge carrier
collection efficiency ηCTηCC can be made. Thus, the inner enhancement of exciton diffusion efficiency ηED is discovered
with the assistance of longer triplet exciton diffusion length of (t-bt)2Ir(acac).
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.