Related Experiment Video
Updated: Dec 6, 2025
08:12
Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
9.9K
Spectrum projection with a bandgap-gradient perovskite cell for colour perception.
Mei-Na Zhang1, Xiaohan Wu1, Antoine Riaud1
1State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433 China.
Light, Science & Applications
|October 5, 2020
Summary
Researchers developed a novel bandgap-gradient perovskite cell that mimics human vision to perceive light intensity and color. This single device simplifies spectrum processing for various optoelectronic applications.
Area of Science:
- Optoelectronics
- Materials Science
- Spectroscopy
Background:
- Optoelectronic devices are crucial for sensing, imaging, and optical communications.
- Current photodetectors lack spectral information, while spectrometers can be complex and generate redundant data.
- Human visual perception compresses spectral information into intensity and color, simplifying processing.
Purpose of the Study:
- To propose and demonstrate a single-device spectrum projection concept for intensity and color perception.
- To simplify spectrum processing in optoelectronic applications by mimicking human visual perception.
- To develop a bandgap-gradient semiconductor cell for efficient spectrum analysis.
Main Methods:
- Fabrication of a bandgap-gradient perovskite photoactive layer using a halide-exchanging method.
- Development of a cell producing two distinct output signals: one sensitive to photon energy and flux, the other to flux only.
- Combining signals to project spectra into photon flux (intensity) and average photon energy (hue).
Main Results:
- The fabricated cell demonstrated linear responses to photon energy and flux.
- The device successfully projected monochromatic and broadband spectra into intensity and hue, correlating well with commercial instruments.
- Real-time, instantaneous intensity and hue results were achieved under changing illumination.
- The device showed potential for chemical/bio-sensing through color comparison.
Conclusions:
- A single, human-visual-like device for spectrum projection and color perception was successfully developed.
- The bandgap-gradient perovskite cell offers a paradigm for high-efficiency spectrum processing.
- This approach simplifies spectral analysis for diverse optoelectronic applications.
More Related Videos
Related Concept Videos
01:24Color Vision
1.1K
Color perception begins in the retina, the light-sensitive layer at the back of the eye. Two main theories explain how colors are seen: the trichromatic theory and the opponent-process theory. The trichromatic theory, proposed by Thomas Young in 1802 and extended by Hermann von Helmholtz in 1852, suggests that color vision is based on three types of cone receptors in the retina. These cones are sensitive to different but overlapping ranges of wavelengths corresponding to red, blue, and green.
1.1K
01:22Photoreceptors and Visual Pathways
8.2K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
8.2K
01:32UV–Vis Spectroscopy of Conjugated Systems
8.0K
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent of conjugation in...
One of the factors influencing λmax is the extent of conjugation in...
8.0K
01:20Anatomy of the Eyeball
9.1K
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle...
9.1K
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
2.4K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
2.4K
01:21G-Protein Gated Ion Channels
5.3K
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory...
Sensory...
5.3K