Free tools Windows power users keep installed
One-click scans. No signup required.
A six-junction solar cell developed by NREL researchers reached 47.1% conversion efficiency in a 2020 test using direct-spectrum sunlight concentrated to 143 suns. That was a laboratory concentrator-cell record when reported—not a measurement for a standard rooftop panel. The overall record has since moved on: Fraunhofer ISE currently lists a different cell at 47.6%.
What did the six-junction cell achieve?
The 2020 result was 47.1% efficiency for a monolithic, series-connected, six-junction inverted metamorphic III–V cell tested under the direct spectrum at 143 suns. The result was reported by Geisz and colleagues in NREL’s research record and published in Nature Energy. It describes conversion by a solar cell under specified laboratory conditions, not the output or efficiency of a complete commercial module.
The headline number depends on the test conditions. “143 suns” means the cell was illuminated with concentrated sunlight; it is not the same condition as sunlight falling on a conventional panel without concentration. NREL separately reported 39.2% for a six-junction cell under one-sun global illumination in a 2020 result noted in a 2022 NREL release. These figures describe different illumination conditions and should not be compared as if they were the same test.
How does a six-junction solar cell work?
A multijunction cell stacks semiconductor subcells with different bandgaps. Each junction responds to a different portion of the solar spectrum, allowing the device to convert a broader range of light than a single-junction cell can. In the six-junction design, the subcells are integrated into one monolithic, series-connected device.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
That architecture is part of why the test setup matters: the reported 47.1% was achieved with concentrated direct-spectrum light. To compare efficiency claims meaningfully, check the junction count, whether the result is for a concentrator or one-sun test, the spectrum and concentration used, and whether the figure applies to a cell or a module.
Is 47.1% still the solar-cell efficiency record?
No. The six-junction result was a record when it was reported, but Fraunhofer ISE’s current institutional page identifies a 47.6% four-junction wafer-bonded concentrator cell as the world’s most efficient solar cell. See Fraunhofer ISE’s III-V solar cells, modules and concentrator photovoltaics page. The six-junction result remains a significant milestone for that specific architecture; it should not be described as the current overall record.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Where are multijunction concentrator cells used?
Concentrator photovoltaics (CPV) use optics to focus sunlight onto high-efficiency cells. Fraunhofer ISE describes CPV as suited to locations with strong direct normal irradiation and large power-plant settings. This is a different operating context from a conventional flat-plate rooftop panel, which receives diffuse as well as direct light. III–V solar cells also have research and application contexts in space. Fraunhofer’s III-V high-efficiency solar cells page provides institutional background on the technology.
A high cell-efficiency result alone does not establish the cost, efficiency, or commercial availability of a complete system. The 47.1% figure is evidence of what this specialized cell achieved in its reported test, not proof that a six-junction product is available or suitable for a home installation.
Recommended Free Tools
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
