Year 2014 face_with_colon_three
The incredible drop in the price of solar energy will shake up our world.
Category: solar power
Highly Efficient Perovskite/CIGS Tandem Enabled by Modification of Band Profile of CIGS Bottom Cell
This study examined the potential of narrow-bandgap (Perovskite-based tandem solar cells are a promising photovoltaic (PV) technology to exceed the Shockley–Queisser limit of single-junction solar cells. Perovskite/Si tandem solar cells have been intensively studied, demonstrating a record power conversion efficiency (PCE) of 34.6% [1]. In contrast, the certified record PCE of perovskite/Cu(In, Ga)Se2 (CIGS) tandem solar cells remains 24.6% with a reported efficiency of 24.9% [1, 2]. Theoretical calculations for double-junction tandem solar cells using a detailed balance model indicate that the bandgap (Eg) combinations of 1.12 eV (for a bottom cell) and 1.70 eV (for a top cell) or 0.90 to 1.04 eV (for a bottom cell) and 1.58 to 1.67 eV (for a top cell) can yield a maximum theoretical tandem efficiency [3, 4]. Wide-bandgap perovskite (with Eg equal to or greater than 1.7 eV) has been actively studied for tandem application with Si (Eg = 1.12 eV), the most successful solar cell technology to date as a bottom cell. However, previous studies have shown that wide-bandgap perovskite suffers from substantial open-circuit voltage (VOC) loss due to halide segregation [5], and the maximum PCEs of single-junction perovskite cells have been produced by perovskite with Eg between 1.52 and 1.63 eV [6– 8]. The bandgap of CIGS can be tuned between 1.01 and 1.68 eV by adjusting the Ga/(Ga+In) (GGI) ratio and through tuning of bandgap grading profile [9]. Employing a narrow-bandgap CIGS close to 1.00 eV as a bottom cell is advantageous to use the most efficient, conventional bandgap perovskite as the top cell. Therefore, unlike Si, the bandgap tunability of CIGS offers an opportunity for perovskite/CIGS to attain a greater ultimate performance than perovskite/Si tandem solar cells. Han et al. [10] introduced a thick indium-doped tin oxide (ITO) recombination layer to bury the intrinsic surface roughness of CIGS, followed by chemical mechanical polishing to prepare a smooth surface for the subsequent solution process of perovskite, attaining a certified PCE of 22.4%. Albrecht and coworkers have improved the PCE of perovskite/CIGS tandem solar cells by modifying the hole transport layer (HTL). In their earlier work, a NiOx/PTAA bilayer was utilized to form a uniform HTL on CIGS bottom cells. Recently, a self-assembled monolayer such as 2PACz and Me-4PACz was used, which can enhance the device performance of single-junction perovskite solar cell and its perovskite/CIGS tandem counterpart, achieving a certified PCE of 24.2% [2, 11 – 13].
Most recent studies on perovskite/CIGS tandem solar cells have focused on optimizing the perovskite top cell. In contrast, all CIGS bottom cells include an absorber with a double-graded (DG) bandgap profile optimized around the bandgap of ~1.1 eV. The DG bandgap profile has been adapted primarily for CIGS absorbers prepared by thermal evaporation, which has resulted in high-performing CIGS solar cells with PCEs up to 23.4% [14], and it has proven to be an effective strategy for enhancing performance, optimized for “single-junction” CIGS; however, it has not been determined whether DG would be the ideal configuration for tandem applications. Kim et al. [15] used single-graded (SG) CIGS with a bandgap close to 1.0 eV, where the band grading is only formed on the backside of the absorber. They employed dual alkali post-deposition treatment (PDT) with KF and CsF, demonstrating a CIGS solar cell with a PCE of 20.
Sorting out a dielectric mismatch boosts perovskite/silicon tandem solar cells’ efficiency and durability
Solar cells, devices that can convert sunlight into electricity, are now widely used in many countries and are contributing to the reduction of greenhouse gas emissions on Earth. While most of the solar cells on the market today are based on silicon, energy engineers have been exploring the potential of other photovoltaic materials, including a class of materials known as perovskites.
Perovskites are materials with a characteristic crystal structure; the same structure of the mineral calcium titanium oxide CaTiO3. A promising solar cell design introduced over the past decades entails the stacking of silicon and perovskite layers to produce so-called tandem cells, a type of photovoltaics that can capture a broader range of the solar spectrum than single-layer solar cells.
Perovskite/silicon solar cells have been found to exhibit remarkable power conversion efficiencies, which essentially means that they convert a higher percentage of sunlight into electricity. Nevertheless, under some conditions (e.g., when they are situated in partly shaded areas) their performance tends to rapidly degrade over time.
Quantum computing could transform energy grid optimization and security
Modern power systems are rapidly evolving into highly digitized smart grids, increasing their complexity at an unprecedented pace. Renewables, batteries, electric vehicles, power electronics, sensors and real-time control systems are all expanding rapidly, and this is making electricity grids significantly harder to simulate, optimize, secure and operate.
This is driven by the increasing energy demands of a tech-driven modern world. Think of a suburban street in 2005—every house pulled electricity from the grid, and power flowed in one direction from big power stations.
This same street in 2026 might have houses with rooftop solar exporting power back into the grid; electric vehicles (EVs) that need to charge overnight; home batteries storing solar energy and feeding it back into the grid when prices spike; electric busses, electric irrigation pumps, automated machinery and smart appliances that turn on and off based on grid signals.
Quantum vibronics research points to future energy and computing technologies
Scientists at the University of California, Riverside are making breakthroughs in understanding how quantum wave functions move across ultra-thin materials—research that could eventually improve solar energy technologies and help lay the groundwork for new forms of quantum computing.
The researchers are part of UCR’s Center for Quantum Vibronics in Energy and Time (QuVET), which was established two years ago and focuses on “vibronics,” the interaction between vibrations and electronic quantum states. The center examines both biological molecules and synthetic layered materials, where the same fundamental quantum processes emerge across vastly different systems.
Its research brings together physicists, chemists, engineers, and biochemists from multiple institutions to better understand how vibrations shape quantum behavior.
Researchers push back fundamental limit on energy transfer between particles without ‘spilling’ radiation
Researchers at TU/e have demonstrated that energy transfer without loss via light or heat can occur over much greater distances than previously thought possible thanks to vibrations in microscopic gold rods. They succeeded in making energy jump from one particle to another over a distance of several millimeters without “spilling” energy along the way.
In the microscopic world in which this research takes place, that is a giant leap, with promising applications in quantum communication, solar energy, and ultrasensitive medical sensors. The researchers have published their findings in the journal Science Advances.
Normally, a molecule that absorbs energy loses it again as heat through vibrations passed on to the surrounding environment or as a particle of light (known as a photon). In Förster resonance energy transfer (or FRET for short, which is named after the German physicist Theodor Förster), something different happens: the energy jumps directly, without radiation, from one molecule to a specific neighboring molecule through an invisible interaction between their electric fields.
Supercharging solar cells: Quantum dot-molecule hybrid states enable near-maximum efficiency
Solar panels have become more efficient over the years, but even the best designs still lose a large fraction of the energy they absorb. Scientists around the world have been searching for ways to capture more energy from every ray of sunlight and unlock the true potential of solar technology.
In a study published in Nature Photonics, researchers from the University of Osaka and collaborating institutions identified a new mechanism that could help us do exactly that. The study shows how specially designed combinations of molecules and quantum dots can be used to dramatically increase solar cell efficiency beyond currently known limits.
Singlet exciton fission is a photophysical phenomenon in which one particle of light creates two excited energy states instead of one. In theory, this allows solar cells to generate more electricity from the same amount of sunlight. However, the most effective photophysical processes require extra energy and are usually inefficient and difficult to control.
AI speeds up discovery of next-gen computer chips and electronic materials
An international study team, led by Flinders University in collaboration with Khalifa University UAE, built the machine-learning platform to act like a “smart materials discovery engine,” which is capable of dramatically reducing the time spent on complex computer or lab experiments to test and find new materials for future semiconductors.
Semiconductors are used in high-tech applications from wearable electronics, communication systems and smartphones to medical and LED devices and solar panels.
“The challenge is that there are millions of possible material combinations, and testing them one by one in the laboratory or with complex computer simulations is extremely slow and expensive,” says Flinders University ARC Future Fellow Associate Professor Vi-Khanh Truong, lead author of a new article in ACS Materials Letters, titled “Bayesian optimization-guided discovery of gallium-containing semiconductors with targeted band gaps.”
MIT researchers use AI to uncover atomic defects in materials
In biology, defects are generally bad. But in materials science, defects can be intentionally tuned to give materials useful new properties. Today, atomic-scale defects are carefully introduced during the manufacturing process of products like steel, semiconductors, and solar cells to help improve strength, control electrical conductivity, optimize performance, and more.
But even as defects have become a powerful tool, accurately measuring different types of defects and their concentrations in finished products has been challenging, especially without cutting open or damaging the final material. Without knowing what defects are in their materials, engineers risk making products that perform poorly or have unintended properties.
Now, MIT researchers have built an AI model capable of classifying and quantifying certain defects using data from a noninvasive neutron-scattering technique. The model, which was trained on 2,000 different semiconductor materials, can detect up to six kinds of point defects in a material simultaneously, something that would be impossible using conventional techniques alone.
Orbital Data Centers: Power and Thermal Management for Scalable Architectures
Redwire’s latest whitepaper examines the challenges and opportunities associated with scaling orbital data centers (ODCs), with a focus on power generation and thermal management. ODCs could eventually surpass terrestrial data centers by leveraging abundant solar energy in space and avoiding Earth-based infrastructure limitations.
The whitepaper examines the scaling of power and thermal systems for ODCs within a single-spacecraft architecture and highlights how the future success of ODCs will depend on treating power and thermal management as primary architectural drivers from the earliest stages of design.
Drawing on decades of Redwire’s spaceflight heritage in deployable structures, high-power solar arrays, and thermal management systems, the in-depth study also highlights how existing flight-proven technologies can support practical and scalable orbital compute architectures.