Ternary organic solar cells enjoy both the enhanced light absorption by incorporating multiple organic materials in tandem solar cells and the simplicity of processing conditions that are used in single bulk heterojunction solar cells.

Ultraviolet (UV) radiation has a variety of impacts including the health of humans, the production of crops, and the lifetime of buildings. Based on the photovoltaic effect, self-powered UV photodetectors can measure and monitor UV radiation without any power consumption. However, the current low photoelectric performance of these detectors has hindered their practical use. In our study, a super-high-performance self-powered UV photodetector based on a GaN/Sn:Ga 2 O 3 pn junction was generated by depositing a Sn-doped n-type Ga 2 O 3 thin film onto a p-type GaN thick film. The responsivity at 254 nm reached up to 3.05 A/W without a power supply and had a high UV/visible rejection ratio of R 254 nm /R 400 nm = 5.9 × 10 3 and an ideal detectivity at 1.69 × 10 13 cm•Hz 1/2 •W −1 , which is well beyond the level of previous self-powered UV photodetectors. Moreover, our device also has a low dark current (1.8 × 10 −11 A), a high I photo /I dark ratio (∼10 4 ), and a fast photoresponse time of 18 ms without bias. These outstanding performance results are attributed to the rapid separation of photogenerated electron−hole pairs driven by a high built-in electric field in the interface depletion region of the GaN/ Sn:Ga 2 O 3 pn junction. Our results provide an improved and easy route to constructing high-performance self-powered UV photodetectors that can potentially replace traditional high-energy-consuming UV detection systems. KEYWORDS: self-powered, ultraviolet photodetector, GaN/Sn:Ga 2 O 3 pn junction, superhigh photoresponsivity, 3.05 A/W, potential barrier U ltraviolet radiation has a significant impact on humankind. Some benefits are UV's ability to facilitate the synthesis of vitamin D, kill germs, and treat or prevent rickets when our skin is exposed to moderate UV light. 1 However, it can cause cataracts and skin cancer and accelerate the aging process due to an excessive amount of UV radiation. 1,2 Additionally, UV radiation strongly affects the production of crops and the lifetime of buildings. Fortunately, UV radiation can be measured and monitored using semiconductor UV photodetectors based on Einstein's photoelectric effect, which transforms UV radiation to measurable electronic signals. After decades of steady development, modern UV photodetectors, with high performances in photoresponsivity, signal-to-noise ratios, stability, and speed, have gained interest recently for their applications in environmental monitoring, advanced communications, air purification, leak detection, space research, etc. 3−13 Unfortunately, to acquire reasonable detectivity, an external electric field is applied to photodetectors to separate the photogenerated electron−hole pairs. 5−13 Therefore, external power sources are generally necessary. This makes photodetectors overall uneconomical and complex. On the contrary, self-powered photodetectors can help solve the energy issues and have attracted significant attention. 14−19 Compared to traditional photodetectors, self-powered structures, based on the photovoltaic effect su...

Since 2009, perovskite solar cells (PSCs) have witnessed dramatic development with the record power conversion efficiency (PCE) breaking 25% within one decade. One bottleneck for the commercialization of PSCs is...

A new electron-rich central building block, 5,5,12,12-tetrakis(4-hexylphenyl)-indacenobis-(dithieno[3,2-b:2',3'-d]pyrrol) (INP), and two derivative nonfullerene acceptors (INPIC and INPIC-4F) are designed and synthesized. The two molecules reveal broad (600-900 nm) and strong absorption due to the satisfactory electron-donating ability of INP. Compared with its counterpart INPIC, fluorinated nonfullerene acceptor INPIC-4F exhibits a stronger near-infrared absorption with a narrower optical bandgap of 1.39 eV, an improved crystallinity with higher electron mobility, and down-shifted highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels. Organic solar cells (OSCs) based on INPIC-4F exhibit a high power conversion efficiency (PCE) of 13.13% and a relatively low energy loss of 0.54 eV, which is among the highest efficiencies reported for binary OSCs in the literature. The results demonstrate the great potential of the new INP as an electron-donating building block for constructing high-performance nonfullerene acceptors for OSCs.

A universal layer-by-layer solution-processing approach is proven to be effective for the fabrication of high-performance non-fullerene organic solar cells.

Rational material design and additive selection boost the longevity of high-efficiency non-fullerene solar cells against photo-oxidation.

This article analyzes and discusses a multi-objective optimization-based layer-by-layer blade-coating approach, which provides a new technology choice for large-scale manufacturing of organic solar cells.

A self-powered ultraviolet photodetector with an extremely high responsivity (54.43 mA W−1) was fabricated by constructing p–n junction of GaN/Ga2O3 films.