- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The impacts of LPCVD wrap-around on the performance of n-type tunnel oxide passivated contact c-Si solar cell
摘要： In this paper, Tunnel Oxide Passivated Contact (TOPCon) silicon solar cells with the industrial area (244.32cm2) are fabricated on N-type silicon substrates. Both the ultra-thin tunnel oxide layer and phosphorus doped polycrystalline silicon (polysilicon) thin film are prepared by the LPCVD system. The wrap-around of polysilicon is observed on the surface of borosilicate glass (BSG). The polysilicon wrap-around can form a leakage current path, thus degrades the shunt resistance of solar cells, and leads to the degradation of solar cell efficiency. Different methods are adopted to treat the polysilicon wrap-around and improve shunt resistance of solar cells. The experimental results indicate that a chemical etching method can effectively solve the problem of polysilicon wrap-around and improve the performance of solar cells. Finally, a conversion efficiency of 22.81% has been achieved by our bifacial TOPCon solar cells, with Voc of 702.6 mV, Jsc of 39.78 mA/cm2 and FF of 81.62 %.
关键词： LPCVD,wrap-around,Tunnel oxide passivated contact,polycrystalline silicon thin film
更新于2025-09-23 15:21:01
-
Development of ultra-thin doped poly-Si via LPCVD and ex-situ tube diffusion for passivated contact solar cell applications
摘要： Rear side application of polycrystalline silicon (poly-Si) passivated contacts has demonstrated very high efficiencies for single-junction monocrystalline silicon (mono-Si) solar cells. To further improve the device performance, one possible approach is to apply the passivated contact concept to the front side of the solar cell as well. The front side application requires the use of ultra-thin poly-Si layer in order to suppress parasitic absorption. Suitable ex-situ diffusion process should be developed accordingly without damaging the passivation provided by the very thin interface oxide (iOx). In this work, we prepared symmetric lifetime samples of ultra-thin poly-Si (<30 nm) via low pressure chemical vapour deposition (LPCVD) method. Then we studied and optimised the ex-situ POCl3/BBr3 diffusion doping processes. An excellent passivation quality was demonstrated with a high implied open-circuit voltage (iVoc) of up to 730 mV (on symmetric n+ poly-Si lifetime samples) and 700 mV (on symmetric p+ poly-Si lifetime samples). For possible contact formation, we capped the poly-Si with sputter-deposited ZnO:Al, which shows good opto-electrical properties and firing stability at 650 °C.
关键词： Diffusion,ZnO:Al,Ex-situ doping,Ultra-thin poly-Si,Passivated contact
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Ultra-thin LPCVD SiN <sub/>x</sub> /n+poly-Si passivated contacts a?? A possibility?
摘要： This work explores the possibility of using ultrathin silicon nitride (SiNx) films with high positive fixed charge in a SiNx/poly-Si passivating contact. The factors including (i) film thickness, (ii) annealing condition (time, temp and ambient) and (iii) surface pre-treatment were optimized to boost the passivation performance of ultrathin LPCVD SiNx films. Our preliminary experiments reveal excellent surface passivation and low recombination current density, Jo (45 fA.cm-2) by ~1.5 nm thick LPCVD SiNx films when subjected to an air ambient anneal at 800?C for 30 mins. This is due to the formation of high positive fixed charge density (1.5 ?10 12 cm-2). Air ambient annealed (465 μs) samples also have a higher lifetime when compared to the forming gas annealed (208 μs) samples. These passivating SiNx films were further integrated into SiNx/n+poly-Si contacts and characterized for Jo,contact and tunneling resistance, ?contact. The best SiNx/n+poly-Si passivated contact in this study has Jo, contact = 5.9 fA.cm-2, ?contact = 0.525 Ω.cm2 and an efficiency potential > 22.75%. According to our knowledge, it is the first report confirming the formation of passivated contacts with SiNx as the dielectric tunnel layer.
关键词： poly-Si,TEM,LPCVD SiNx,annealing,lifetime studies,passivated contact,silicon nitride,tunnel layer
更新于2025-09-23 15:19:57
-
In-situ phosphorus-doped polysilicon prepared using rapid-thermal anneal (RTA) and its application for polysilicon passivated-contact solar cells
摘要： A rapid thermal anneal (RTA) is used to crystallize the plasma-enhanced chemical vapor deposition (PECVD) deposited hydrogenated amorphous silicon (a-Si:H) thin film to form the phosphorus-doped polysilicon passivated contact in tunnel oxide passivated contact (TOPCon) solar cells. The effects of annealing temperature, annealing time, cooling time, and the polysilicon thickness on the surface passivation are investigated. The primary advantage of the RTA is reducing the whole crystallization period to ~15 min, shorter than the conventional tube-furnace annealing period of >60 min. We find that the RTA is a robust method to prepare high-quality polysilicon passivated contact without introducing blistering when the thickness of the a-Si:H is less than 40 nm. The optimized RTA process leads to an implied open-circuit voltage (iVoc) of 712 mV and a single-sided dark saturation current density (J0,s) of 12.5 fA/cm2 in the as-annealed state, which is inferior to the surface passivation of the controlled one prepared by a tube furnace annealing. Fortunately, a subsequent Al2O3 capping hydrogenation improves the iVoc and J0,s to 727 mV and 4.7 fA/cm2, respectively. The champion conversion efficiency of 23.04% (Voc ? 679.0 mV, Jsc ? 41.97 mA/cm2 and FF ? 80.86%) is achieved, which demonstrates the effectiveness of RTA for preparing a high-efficiency polysilicon passivated-contact solar cell.
关键词： Rapid thermal anneal (RTA),Polysilicon passivated contact,c-Si,Solar cell,PECVD,TOPCon
更新于2025-09-23 15:19:57
-
The Effect of Crystallographic Orientation and Nanoscale Surface Morphology on <i>Poly</i> -Si/SiO <i> <sub/>x</sub></i> Contacts for Silicon Solar Cells
摘要： High-efficiency crystalline silicon (Si) solar cells require textured surfaces for efficient light trapping. However, passivation of a textured surface to reduce carrier recombination is difficult. Here, we relate the electrical properties of cells fabricated on a KOH-etched, random pyramidal textured Si surface to the nanostructure of the passivated contact and the textured surface morphology. The effects of both microscopic pyramidal morphology and nanoscale surface roughness on passivated contacts consisting of a polycrystalline Si (poly-Si) deposited on top of an ultrathin, 1.5–2.2 nm, SiOx layer is investigated. Using atomic force microscopy we show a pyramid face, which is predominantly a Si(111) plane to be significantly rougher than a polished Si(111) surface. This roughness results in a nonuniform SiOx layer as determined by transmission electron microscopy (TEM) of a poly-Si/SiOx contact. Our device measurements also show an overall more resistive, and hence thicker SiOx layer over the pyramidal surface as compared to a polished Si(111) surface, which we relate to increased roughness. Using electron-beam-induced current measurements of poly-Si/SiOx contacts we further show that the SiOx layer near the pyramid valleys is preferentially more conducting, and hence likely thinner than over pyramid tips, edges and faces. Hence, both the microscopic pyramidal morphology and nanoscale roughness lead to nonuniform SiOx layer, thus leading to poor poly-Si/SiOx contact passivation. Finally, we report >21% efficient and ≥80% fill-factor front/back poly-Si/SiOx solar cells on both single-side and double-side textured wafers without the use of transparent conductive oxide layers and show that the poorer contact passivation on a textured surface is limited to boron-doped poly-Si/SiOx contacts.
关键词： passivated contact,tunneling,silicon oxide,electron beam induced current,silicon solar cell,surface orientation,atomic force microscopy
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Luminescent Solar Concentrator Tandem-on-Silicon with above 700mV Passivated Contact Silicon Bottom Cell
摘要： Luminescent solar concentrator (LSC) tandem-on-silicon (Si) provides a route towards achieving higher than 30% overall efficiency which can overcome the theoretical efficiency limit of a single junction Si cell. Here, we present optical coupling and performance of high Voc passivated contact Si bottom cell for LSC tandem-on-Si where the top module consists of highly efficient luminophores and an array of micro InGaP cells embedded in a poly (lauryl methacrylate) waveguide. In this device configuration, InGaP cell area coverage is only ~0.5% of the total LSC area which significantly reduces the high cost III-V material usage. The performance of Si sub-cell is investigated under LSC spectrum and is compared against the measurement done under 1 μm thick InGaP filter which mimics the spectrum seen by Si bottom cell in a conventional III-V/Si tandem. Voc of greater than 700 mV has been observed for the passivated contact Si bottom cell in these tandem applications.
关键词： passivated contact cells,luminescent solar concentrator,silicon
更新于2025-09-19 17:13:59