Photon Crystal Energy, a companyspecializing in perovskite components, has announced the successful completion of its Angel round funding of RMB 30 million, with participation from Sinovation Ventures, Dingxiang Capital, and led byZhengxuan Investment. The company has achieved an impressive 20% efficiency on a 20 cm x 20 cm perovskite component and has already developed a 10 MW pilot line for a 30 cm x 30 cm component, targeting a similar 20% efficiency rate.
PhotonCrystal Energy’s 30 cm × 30cm perovskite samples
The national objectiveof achieving carbon neutrality has made the development of renewable energy, such as photovoltaic solar energy, a top priority. Thanks to the "dual carbon" policy and the attainment of grid parity, which has led to a decline in costs, the PV industry is experiencing a new stage of development driven by market demand. As a world leader in China, the photovoltaic sector has created a new infrastructure market worth hundreds of billions of dollars due to strong domestic and international demand for clean energy. This new market is expected to continue to grow over the next few decades. It is estimated that in 2022, the global installed capacity of PV will reach 250 GW, with a year-on-year growth rate of 47%, and in 2025, it will reach 330 GW, indicating significant market potential.
The photovoltaicindustry has evolved from first-generation crystalline silicon cells and second-generation thin-film cells to third-generation photovoltaic cells, represented by perovskite. Perovskite cells have several advantages, such as high theoretical conversion efficiency, low material, and production costs, and good low-light performance. Though they face technical challenges, such as difficulty in large-area preparation and relatively weak stability, they have enormous potential and will be a robust alternative to crystalline silicon cells once technological breakthroughs are achieved.
Traditional crystallinesilicon photovoltaic components production requires four factories: the first factory extracts silicon metal from silicon sand, produces high-purity silicon through refined extraction and reduction; the second transforms high-purity silicon into perfectly crystallized silicon rods in a single crystal furnace and cuts them into silicon wafers with diamond wire; the third processes silicon wafers into cells through cleaning, diffusion, coating, screen printing, etc.; and the fourth assembles cells and auxiliary materials into components. This process is time- and energy-consuming. In contrast, perovskite PV components' raw materials are bulk chemicals, which are cheap and easily available. The process is short and can be completed in a single factory, requiring only a few steps such as coating, laser cutting, and encapsulation. The investment cost of a single GW is about half of that of a crystalline silicon module, and the single-watt energy consumption is only 0.12KWh, one-tenth of that of a crystalline silicon module. Therefore, once perovskite components are produced on a large scale, they will have a significant cost advantage.
Photon Crystal Energy'score team, among the earliest researchers to study the industrialization of perovskite, boasts a wealth of expertise in this field. The company's CEO, Dr. Huang Fuzhi, holds the esteemed position of director at the Advanced Thin Film Photovoltaic Research Center, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology. He has authored over 150 papers in top-tier journals such as Science and Nature, with more than 10,000 citations to his name. Since returning to China in 2015, Dr. Huang has focused on advancing the industrialization technology of perovskite PV cells. He has even developed an exclusive perovskite ink printing technology and published a Science paper as the sole corresponding author.
Dr. Huang Fuzhi, CEO ofPhoton Crystal Energy, asserts that the key to overcoming the hurdle of large-scale industrialization of perovskite PV components lie in striking a balance between power conversion efficiency (PCE), area, and stability.
Perovskite solar cellshave made significant strides in efficiency, with power conversion efficiency (PCE) no longer a bottleneck for industrialization. After a decade of development, the laboratory PCE of tandem perovskite cells has reached 31.3%, and that of single-junction cells has reached 25.7%. This compares favorably to the nearly 40 years it took to raise the PCE of crystalline silicon cells to 26%, which are currently in mainstream use. However, the theoretical limit of PCE for crystalline silicon cells is 29.43%, leaving a limited potential for improvement.
When asked why PhotonCrystal Energy is prioritizing the industrialization of single-junction perovskite cells rather than tandem perovskite cells with higher PCE efficiency, CEO Dr. Huang Fuzhi explained that while the laboratory PCE of tandem perovskite cells is higher, the technology requires covering perovskite to the surface of crystalline silicon cells or another layer of perovskite, which exponentially increases the risk of industrialization. Single-junction perovskite technology is the root of perovskite PV technology, providing a foundation for the development of flexible, tandem, and other types of cells.
The unclear pathway forthe industrialization of perovskite cells in general poses a risk to the industrialization of tandem perovskite components. Their stability and life cycle will remain below par for some time to come. For instance, in perovskite/silicon two-terminal tandem solar cells, if the perovskite cell layer ceases to be effective earlier than the crystalline silicon layer, renders the whole component worthless. Furthermore, perovskite/perovskite tandem cells often require the addition of Sn2+, Br-, and other elements to enhance light absorption, making them less stable than conventional perovskite and requiring two rounds of perovskite film preparation. Large-scale preparation of these tandem cells will encounter greater challenges in process and equipment. Therefore, the industrialization of single-junction perovskite cells has become the company’s current focus, said Dr. Huang Fuzhi.
In the quest for theindustrialization of perovskite PV, mass production of perovskite cells has been impeded by the tendency of perovskite crystals to grow in a disorderly manner during the drying process after coating with perovskite ink. This disorderly growth leads to a high number of holes in the crystals, resulting in a significant drop in the PCE of the components due to leakage. Hence, improving the large-scale preparation of perovskite components remains the key challenge to overcome.
Perovskite solar cellshave achieved an impressive power conversion efficiency (PCE) exceeding 25%, as observed under laboratory conditions utilizing the spin-coating method. This process enables uniform distribution of perovskite crystals and consequently higher PCE. Nonetheless, the method's limited substrate size, generally less than 1 cm2, and low material efficiency of 3% restrict its scalability for large-scale production.
The use of the Slot-diecoating method has become prevalent for the production of larger-area perovskite PV components, although the power conversion efficiency (PCE) of these components is significantly impacted as the area increases. Despite a laboratory PCE of 25.7%, Mr. Huang and his industry peers continue to strive towards achieving 16%-18% PCE for square meter-level perovskite cells. This goal is in contrast to the PCE of large-area crystalline silicon components, which can be elevated to 20% and above. Failure to surpass the 18% PCE figure for mass-produced perovskite components could severely undermine its cost advantage per kilowatt-hour despite its low manufacturing cost.
Photon Crystal Energyhas unveiled an innovative solution to curb the challenge of chaotic perovskite crystal growth. The firm has formulated an exclusive perovskite ink blend that effectively curtails the generation of such crystals during the coating process. The new ink creates a densely structured film, which only starts developing perovskite crystals when the annealing process kicks off, thus avoiding the scourge of wayward crystal growth during drying. Importantly, the advanced ink also allows for continuous slot-die coating, resulting in improved efficiency and productivity.
High-precisionslot-die coater used by the company (partial)
To improve the stability of perovskite solar cells, Dr. Shi Lei, the company's CTO,proposed the idea of a hermetic environment and developed a fullencapsulation technology for perovskite cells. His research has set a record for thestability of perovskite cells and made him the first author andcorresponding author of a Science paper. His encapsulated cells far exceed the IEC61215 testrequirements such as the Temperature Humidity Bias Test, with almost no degradation for over 1800 hours.
Photon Crystal Energy’s team has rich R&Dexperience in the photovoltaic industry. The company’s chief advisor,Academician Cheng Yibing, is a renowned scientist in the field, with morethan 24,000 citations, including 13 publications in Nature, Science, and Nature sub-journals. Dr. Yao Guoxiao,Vice President of Manufacturing, has extensive experience in the PV industry andwas the CTO of Yingli Solar, a PV energy solution provider listed on NYSE, and the Director andCTO of Jinko Solar. He is responsible for the industrialization of Photon Crystal Energy’s technology.
Photon Crystal Energyplans to build a 100 MW pilot line of 60 cm×120 cm components in 2023 and achieve mass production of a 100-MW line in 2024.