Contact Solar Cells Research Articles

Titanium‐Oxide‐Based Electron‐Selective Contact for Ultrathin Germanium Quantum Well Solar Cell

In solar cells with an optical cavity as a light trapping mechanism, parasitic absorption is among the main detrimental optical losses. One approach to reducing these losses is the implementation of charge carrier‐selective contacts with wide bandgaps using thin metal oxides like titanium oxide (TiOx). Herein, it is proved that TiOx is a suitable alternative for lossy n‐doped hydrogenated amorphous silicon (n a‐Si:H) as electron selective contact in ultrathin solar cells based on intrinsic hydrogenated amorphous germanium (a‐Ge:H). The integration of the TiOx layer leads to an improved photocurrent generation in the blue light wavelengths. Furthermore, a substantial extraction of charge carriers is demonstrated from the a‐Ge:H quantum well nanoabsorber embedded between intrinsic a‐Si barrier layers. However, the substitution of n a‐Si:H by TiOx results in limited photovoltaic performance due to a lower open‐circuit voltage. This effect is analyzed via electrical simulation considering a variation in the electron affinity and the doping of TiOx as well as the defect density in the silicon buffer. Moreover, the TiOx‐based solar cell exhibits improved light transmittance when the opaque back contact is omitted, which is beneficial for semi‐transparent applications.

Exploration of Phosphorus Oxide in Heavily Phosphorus-Doped Polysilicon Films of Tunneling Oxide Passivation Contact Solar Cells

Exploration of Phosphorus Oxide in Heavily Phosphorus-Doped Polysilicon Films of Tunneling Oxide Passivation Contact Solar Cells

Comparing the Gettering Effect of Heavily Doped Polysilicon Films and Its Implications for Tunnel Oxide‐Passivated Contact Solar Cells

In addition to excellent surface passivation and carrier selectivity, the structure based on the heavily doped polysilicon layer on an ultrathin silicon oxide interlayer also demonstrates strong impurity gettering effects. Herein, the gettering strength of a range of phosphorus‐ or boron‐doped polysilicon films from different fabrication techniques is assessed and compared. Iron, one of the most common metallic impurities in silicon, is used as a tracer impurity to quantify the gettering strength (segregation coefficient). A comparison of the experimental results to the literature, combined with measurements of the electrically active and inactive dopant concentrations, enables us to suggest the main gettering mechanisms in different polysilicon films. The differences in the segregation coefficients of the phosphorus‐doped polysilicon films for iron are within one order of magnitude, in spite of their different combinations of gettering mechanisms. On the other hand, boron‐doped polysilicon films show a large variation in their gettering effects, although the predominant gettering mechanisms are all attributed to electrically inactive boron, according to the current understanding of the gettering mechanisms from the literature. Finally, the impact of different polysilicon gettering effects on the efficiency of tunnel oxide‐passivated contact (TOPCon) cells is simulated and discussed.

24.4% industrial tunnel oxide passivated contact solar cells with ozone-gas oxidation Nano SiOx and tube PECVD prepared in-situ doped polysilicon

Ozone-gas oxidation (OGO) technology, capable of integrating into tube plasma-enhanced chemical vapor deposition (PECVD) technology, is developed to prepare the Nano SiO x layer for tunnel oxide passivated contact (TOPCon) solar cells in this work. The effects of gas flow, oxidation temperature, and annealing temperature on passivation quality are investigated. The X-ray photoelectron spectroscopy (XPS) indicates that OGO SiO x possesses a Si 4+ proportion of about 20%, higher than the nitric acid oxidized (NAOS) SiO x and plasma-assisted N 2 O oxidation (PANO) SiO x . The implied open-circuit voltage ( iV oc ) of the hydrogenated lifetime sample is promoted to more than 740 mV with the highest value of 748 mV, corresponding to a lowest single-sided saturation current density ( J 0,s ) of 3.1 fA/cm 2 . The contact resistivity extracted from the Cox-Strack method is < 9 mΩ cm 2 as the annealing temperature is more than 840 °C. Finally, we prepared the large-sized TOPCon solar cells with an average efficiency of 24.37% and a maximum efficiency of 24.41%, respectively. The above work shows that the tube PECVD technology integrated with ozone gas oxidation has the potential for the mass-production TOPCon industry. • Ozone-gas oxidation (OGO) technology is integrated into tube PECVD technology. • OGO SiO x and P-doped a-Si:H can be prepared by the same graphite-boat carrier. • OGO SiO x shows a high proportion of Si 4+ without ion bombardment. • The highest iV oc of 748 mV corresponding to the lowest J 0,s of 3.1 fA/cm 2 . • Average efficiency of 158.75 mm TOPCon cells reaches ∼24.4%.

Experimental and Numerical Simulation of Molybdenum Oxide Films with Wide Bandgap and High Work Function for Carrier-Selective Contact Solar Cells

In silicon heterojunction (SHJ) solar cells, a wide bandgap material with a high work function is widely used as the hole extraction pathway to attain high efficiency. We introduced a molybdenum oxide (MoOx) film as an effective hole-transfer layer in carrier selective contact (CSC) solar cells by virtue of its wide bandgap along with high work function. The passivation characteristics, optical and electrical properties of MoOx films were investigated by differing thickness and work function. The combination of 6 nm hydrogenated intrinsic amorphous silicon (a-Si:H(i)) and 7 nm thermally evaporated MoOx passivation layers provides excellent passivation properties, reduces carrier recombination, and improves the cell performance. The synthesized CSC solar cells showed promising results, with an open-circuit voltage (Voc) of 708 mV, short-circuit current (Jsc) = 37.38 mA cm−2, fill factor (FF) = 74.59%, and efficiency (η) = 19.75%. To justify the obtained result, an AFORS HET simulation was conducted based on the experimental results. The high work function and wide bandgap MoOx/c-Si(n) interface developed a considerable built-in potential and suppressed the electron–hole pair recombination mechanism. The CSC solar cell’s simulated performance was enhanced from 1.62 to 23.32% by varying the MoOx work function (ΦMoOx) from 4.5 to 5.7 eV.

Sputtered Ultrathin TiO2 as Electron Transport Layer in Silicon Heterojunction Solar Cell Technology.

This work presents the implementation of ultrathin TiO2 films, deposited at room temperature by radio-frequency magnetron sputtering, as electron-selective contacts in silicon heterojunction solar cells. The effect of the working pressure on the properties of the TiO2 layers and its subsequent impact on the main parameters of the device are studied. The material characterization revealed an amorphous structure regardless of the working pressure; a rougher surface; and a blue shift in bandgap in the TiO2 layer deposited at the highest-pressure value of 0.89 Pa. When incorporated as part of the passivated full-area electron contact in silicon heterojunction solar cell, the chemical passivation provided by the intrinsic a-Si:H rapidly deteriorates upon the sputtering of the ultra-thin TiO2 films, although a short anneal is shown to restore much of the passivation lost. The deposition pressure and film thicknesses proved to be critical for the efficiency of the devices. The film thicknesses below 2 nm are necessary to reach open-circuit values above 660 mV, regardless of the deposition pressure. More so, the fill-factor showed a strong dependence on deposition pressure, with the best values obtained for the highest deposition pressure, which we correlated to the porosity of the films. Overall, these results show the potential to fabricate silicon solar cells with a simple implementation of electron-selective TiO2 contact deposited by magnetron sputtering. These results show the potential to fabricate silicon solar cells with a simple implementation of electron-selective TiO2 contact.

Revealing fundamentals of charge extraction in photovoltaic devices through potentiostatic photoluminescence imaging

Revealing fundamentals of charge extraction in photovoltaic devices through potentiostatic photoluminescence imaging

Industrial metallization of fired passivating contacts for n-type tunnel oxide passivated contact (n-TOPCon) solar cells

Poly-Si/SiO x passivating contacts enable the manufacturing of highly-efficient Si solar cells, but their fabrication commonly relies on an extra high-temperature process such as dopant diffusion or thermal annealing for achieving excellent passivation and contacting properties. This extra process is eliminated in the fired passivating contact (FPC) approach used for simplified fabrication of poly-Si/SiO x passivating contacts. Instead, FPCs rely on the thermal budget of the fast/short and high-temperature firing process used for metallization of solar cells to achieve similar final properties. Despite this, compatibility of FPCs with industrially viable metallization techniques has not been demonstrated yet, which is studied in this work for fire-through Ag screen-printing and Ni/Ag plating. With screen-printing, low recombination current density ( J 0 ) down to 4.9 fA/cm 2 , low contact resistivity between the Ag contacts and the FPC ( ρ c,m ) down to 7.2 mΩ⋅cm 2 , and Ohmic transport through the FPC including the SiO x film were achieved using wet-chemically grown SiO x . Nevertheless, J 0 of metallized regions ( J 0,m ) exceeded 1000 fA/cm 2 . Reducing J 0,m was attempted by mitigating the blistering observed in FPCs, but J 0,m remained high. With Ni/Ag plating, excellent surface passivation with J 0 down to 2.7 fA/cm 2 and very low J 0,m < 50 fA/cm 2 were achieved, but no Ohmic contacts could be obtained. Integration of screen-printed FPCs in large-area n-TOPCon solar cells was also demonstrated, yielding average efficiencies of 18.4%, limited mainly by the high J 0,m and series resistance of the FPCs. The results presented reveal the challenges for the industrialization of FPCs and provide valuable insights for tackling these. • Fired passivating contacts (FPCs) developed relying only on the thermal budget of firing and not on conventional annealing. • Compatibility of FPCs with fire-through Ag screen-printing and Ni/Ag plating tested. • Screen-printing: J 0,pass ≈ 5 fA/cm 2 & ρ c < 10 mΩ∙cm 2 achieved, but J 0,metal was high. • Plating: J 0,pass < 3 fA/cm 2 & J 0,metal < 50 fA/cm 2 achieved, but contacts were non-Ohmic. • Integration of FPCs in screen-printed large-area n-TOPCon cells led to 18.4% efficiency.

Emitter formation with boron diffusion from PECVD deposited boron-doped silicon oxide for high-efficiency TOPCon solar cells

We present a systematic study of emitter formation with dopant diffusion from boron (B)-doped hydrogenated silicon oxide (a-SiOx:H) deposited on textured n-type monocrystalline silicon (n-c-Si) wafers using a 13.56 MHz plasma-enhanced chemical vapor deposition (PECVD) system. The B atoms in the a-SiOx:H are activated and diffused into the n-c-Si wafer during a high-temperature annealing to form a p/n junction for solar cell application. Afterward, the B-doped SiOx layer is removed by hydrofluoric acid selective etching to obtain a clean surface for the deposition of AlOx passivation and SiNx antireflection layers. With the optimization of the PECVD deposition and the following annealing/etching processes, the B diffused region with a sheet resistance of 60–100 Ω/sq and a junction depth of 1.2–1.5 μm is obtained. A champion implied open-circuit voltage (iVoc) of 705 mV and a single-side saturated recombination current density (J0,s) of 17.6 fA/cm2 are obtained from a double-sided B diffused sample after the passivation with an atomic-layer-deposition (ALD) AlOx. In addition, the contact resistivity (ρc) at the metal/emitter interface is lower than 5 mΩcm2, where the metal contact is a Ti/Pd/Ag tri-layer structure. All of the material properties meet the requirements of high-efficiency solar cell. With the optimized emitter in the front, we made a SiOx and heavily phosphorus-doped polycrystalline silicon carbide (n-poly-SiCx) stack on the rear surface to form tunnel oxide passivated contact (TOPCon) solar cells. The results show that the iVoc of semi-finished TOPCon solar cell before metallization is more than 725 mV. Finally, a TOPCon solar cell with an efficiency of 24.24% is obtained, which is comparable with the TOPCon solar cells with the industrial thermally diffused emitter.

Chemical stoichiometry effect of hafnium oxide (HfOx) for passivation layer of PERC solar cells

Hafnium oxide (HfOx) is being investigated as a new candidate for the passivation layer of silicon solar cells due to its excellent electrical and optical properties, such as high dielectric constant, large band gap, refractive index, high transparency, and thermodynamic stability in contact with Si. In this paper, the HfOx is analyzed for novel material applied to the passivation layer to improve the performance of passivated emitter and rear contact (PERC) solar cells. For optimisation of the passivation layer of the PERC solar cell, chemical stoichiometry and passivation properties such as interface trap density, fixed charge and effective carrier lifetime are studied before and after the annealing process. After annealing in O2, interface trap density (Dit) decreased from 8.15 × 1010 eV−1cm−2 to 2.37 × 1010 eV−1cm−2 and the fixed charge (Qf) changed from positive to negative after annealing due to the reduction of oxygen vacancies. However, the passivation properties did not meet expectations due to blistering after annealing at 500 °C or higher and the highest effective carrier lifetime was 188.56 μs after annealing at 400 °C, which was improved from 49.48 μs before annealing. It was confirmed that improved passivation performance and solar cell efficiency could be achieved through the chemical stoichiometry effect by a simple annealing process.

High‐Resistance Metal Oxide Window Layers for Optimal Front Contact Interfaces in Sb2Se3 Solar Cells

Herein, an in‐depth experimental investigation into the effect of employing different high resistance metal oxide (HRMO) layers on the quality of the front contact in solar cells with an fluorine‐doped tin oxide (FTO)/(HRMO)/CdS/Sb2Se3/Au device architecture is presented. The application of ZnO or TiO2 HRMO layers between FTO substrates and CdS improves the overall device performance. Short‐circuit current gains of ≈20%, orders of magnitude higher shunt resistances (≈104 Ω cm2), and greatly improved device stabilities—maintaining over 95% of their initial efficiency over 137 days are observed. A suppression of the unfavorable (120) orientation of the photoactive Sb2Se3 layer is observed in devices with HRMO interlayers. The application of HRMO layers is crucial to prevent both ohmic and non‐ohmic current leaks and maintain device stability over time. Cross‐over in the current‐voltage (JV) curves observed in the case of TiO2 indicates the presence of a high barrier for the diode current in these devices. Wavelength‐dependent JV curves coupled with capacitance measurements and simulations show that this barrier can be attributed to a high density of interfacial acceptor states. In contrast, ZnO deposition is found to reduce interface defects and enhance the quality of the front contact, while boosting performance and increasing device longevity.

Solar Cells with Laser Doped Boron Layers from Atmospheric Pressure Chemical Vapor Deposition

We present laser-doped interdigitated back contact (IBC) solar cells with efficiencies of 23% on an area of 244 cm2 metallized by a screen-printed silver paste. Local laser doping is especially suited for processing IBC cells where a multitude of pn-junctions and base contacts lay side by side. The one-sided deposition of boron-doped precursor layers by atmospheric pressure chemical vapor deposition (APCVD) is a cost-effective method for the production of IBC cells without masking processes. The properties of the laser-doped silicon strongly depend on the precursor’s purity, thickness, and the total amount of boron dopants. Variations of the precursor in terms of thickness and boron content, and of the laser pulse energy density, can help to tailor the doping and sheet resistance. With saturation-current densities of 70 fA/cm2 at sheet resistances of 60 Ohm/sq, we reached maximum efficiencies of 23% with a relatively simple, industrial process for bifacial IBC-cells, with 70% bifaciality measured on the module level. The APCVD-layers were deposited with an inline lab-type system and a metal transport belt and, therefore, may have been slightly contaminated, limiting the efficiencies when compared to thermal-diffused boron doping. The use of an industrial APCVD system with a quartz glass transport system would achieve even higher efficiencies.

Losses in bifacial PERC solar cell due to rear grid design and scope of improvement

Photovoltaic (PV) industries are continuously trying to improve the module performance with the adoption of newer cell technologies. Recently, bifacial passivated emitter rear contact (PERC) solar cell technology has entered the market to further improve the module performance through the absorption of the extra photons reflected from the background. This work is mainly focused on optimizing the rear side grid pattern of the bifacial PERC solar cells for improvement of the total output power gain. We have developed an analytical model based on the front and rear grid pattern of commercially available bifacial PERC solar cells to calculate the optical shading and electrical losses for both sides of the solar cells. It is perceived that the rear shading loss due to rear grid design of industrial bifacial PERC solar cells is very high (∼30%) as compared to the front side (∼5%) of the cells. The model calculation shows that if with the improved laser scribing technology the finger width of the rear grid pattern be drastically reduced from ∼ 200 μm (measured value) to 25 μm the optical shading loss may be minimized to 11–14% from 30% without compromising the effective busbar resistance.

Reaction Kinetics Analysis of Treatment Process on Light-Induced Degradation for p-Type Passivated Emitter and Rear Contact Solar Cell Module with Gallium Cz-Si Wafer

The light-induced degradation (LID) phenomenon in solar cells reduces power generation output. Previously, a method was developed to prevent LID where a group III impurity that can replace boron is added to the silicon wafer. However, in a subsequent study, performance degradation was observed in gallium-doped solar wafers and cells, and a degradation pattern similar to that occurring in light and elevated temperature-induced degradation (LeTID) was reported. In this study, a 72-cell module was fabricated using gallium-doped PERC cells, and the treatment of the LID process for carrier injection in the range of 1 to 7 A at 130 °C was analyzed using kinetic theory. We selectively heated only the solar cells inside a 72-cell module using a half-bridge resonance circuit for remote heating. To monitor the treatment of LID process in real time, a custom multimeter manufactured using an ACS758 current sensor and a microcomputer was used. Least-squares curve fitting was performed on the measured data using a reaction kinetics model. When the carrier-injection condition was applied to the gallium-doped PERC solar cell module at a temperature of 130 °C, the observed degradation and treatment pattern were similar to LeTID. We assumed that the treatment rate would increase as the size of the injected carrier increased; however, the 5 A condition exhibited the fastest treatment rate. It was deduced that the major factors of change in the overall treatment of the LID process vary depending on the rate of conversion from the LID state to the treatment state. In conclusion, it can be expected that the deterioration state of the gallium-doped solar cell module changes due to the treatment rate that varies depending on the carrier-injection conditions.

Silicon solar cells with passivating contacts: Classification and performance

AbstractThe year 2014 marks the point when silicon solar cells surpassed the 25% efficiency mark. Since then, all devices exceeding this mark, both small and large area, with contacts on both sides of the silicon wafer or just at the back, have utilized at least one passivating contact. Here, a passivating contact is defined as a group of layers that simultaneously provide selective conduction of charge carriers and effective passivation of the silicon surface. The widespread success of passivating contacts has prompted increased research into ways in which carrier‐selective junctions can be formed, yielding a diverse range of approaches. This paper seeks to classify passivating contact solar cells into three families, according to the material used for charge‐carrier selection: doped amorphous silicon, doped polycrystalline silicon, and metal compounds/organic materials. The paper tabulates their current efficiency values, discusses distinctive features, advantages, and limitations, and highlights promising opportunities going forth towards even higher conversion efficiencies.

An electron-selective SiC /SiO contact for Si solar cells made with fully industrial techniques

We explored the use of inline plasma-enhanced chemical vapor deposition (PECVD) to make P-doped poly-Si/SiO x -type contact for Si solar cells utilizing only industrially viable techniques, especially Ag metallization via screen-printing of a commercial fire-through paste. For this we used a thick (97 nm), non-blistering PECVD Si-rich SiC y layer, called SRC2.0, to minimize the damage due to the aggressive metallization process. The blistering suppression in SRC2.0 is achieved through the incorporation of carbon in the film but comes at the expense of its electrical conductivity. Despite this, ohmic contact between Si and SRC2.0/SiO x could be formed by annealing at 925 °C and higher. Moreover, we discovered that SRC2.0 has a detrimental effect on surface passivation with a thin (1.6 nm) SiO x layer that is typically used with poly-Si. This is due to reduction of the passivating SiO x layer during high-temperature annealing by the high amount (15%) of C in SRC2.0. Using a slightly thicker (1.9 nm) SiO x layer mitigated this effect, and J 0 values of 10 fA/cm 2 and lower (4 fA/cm 2 ), and 40 fA/cm 2 could be obtained in un-metallized and metallized regions, respectively. The best n-type Si solar cell with the SRC2.0/SiO x contact at the rear showed a very high short-circuit current density of 41.4 mA/cm 2 and a good open-circuit voltage of 688.4 mV. Its efficiency was, however, limited to 20.7%. This was due to the high specific contact resistance ((10–40) mΩ·cm 2 ) of the SRC2.0/SiO x contact, which in turn limited the fill-factor of the device to 72.6%. Nevertheless, the trends suggest that better device results can be obtained by using higher thermal budget. • PECVD SiC y layer compatible with industrial Si solar cell fabrication techniques. • SiC y /SiO x contact with screen-printed metallization using fire-through Ag paste. • J 0_pass of 10 fA/cm 2 together with J 0_metal of 40 fA/cm 2 has been demonstrated. • SiC y /SiO x contact employed at the rear of devices with B-diffused front contact. • The best device has a J sc of 41.4 mA/cm 2 , a V oc of 688.4 mV, and a FF of 72.6%.

Advanced Industrial Tunnel Oxide Passivated Contact Solar Cell by the Rear-Side Local Carrier-Selective Contact

In this study, we propose an advanced tunnel oxide passivated contact (TOPCon) solar cell structure for bifacial usage. The proposed structure, named advanced industrial TOPCon (Ai-TOPCon), adopts rear-side local carrier-selective contacts to avoid rear-side light-absorption loss. Ai-TOPCon features larger rear-side light currents and improves the power density by approximately 0.28 mW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for bifacial usage in a 20% albedo scenario. Several types of Ai-TOPCon and industrial TOPCon (i-TOPCon) are evaluated, and the optimization of the structure resulted in a power density of 28.73 mW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Loss analysis revealed that the reduced Auger recombination volume was the main factor contributing to the improvement of cell performance, and the light-absorption problem was solved by reducing the rear-side heavy-doped region.

Impurity Gettering in Polycrystalline‐Silicon Based Passivating Contacts—The Role of Oxide Stoichiometry and Pinholes

AbstractPolycrystalline‐silicon/oxide (poly‐Si/SiOx) passivating contacts for high efficiency solar cells exhibit excellent surface passivation, carrier selectivity, and impurity gettering effects. However, the ultrathin SiOx interlayer can act as a diffusion barrier for metal impurities and this potentially slows down the overall gettering rate of the poly‐Si/SiOx structures. Herein, the factors that determine the blocking effects of the SiOx interlayers are identified and investigated by examining two general types of the SiOx interlayers: 1.3 nm ultrathin tunneling SiOx with negligible pinholes and 2.5 nm SiOx with thermally created pinholes. Iron is used as tracer impurity in silicon to quantify the gettering rate. By fitting the experimental gettering kinetics by a diffusion‐limited segregation gettering model, the blocking effects of the SiOx interlayers are quantified by a transport parameter. Both the oxide stoichiometry and pinhole density affect the effective transport of iron through SiOx interlayers. The oxide stoichiometry depends strongly on the oxidation method, while the pinhole density is affected by the activation temperature, doping concentration, doping technique, and possibly the dopant type as well. To enable a fast gettering process during typical high‐temperature formation of the poly‐Si/SiOx structures, a SiOx interlayer that is less stoichiometric or with a higher pinhole density is preferred.

High efficiency TOPCon solar cells with micron/nano-structured emitter for a balance of light-trapping and surface passivation

At present, conventional micron-pyramid texture is imperfect for further reducing optical reflection loss and improving photoelectric conversion efficiency (PCE) of tunnel oxide passivating contact (TOPCon) solar cells. Herein, reactive ion etching technique is used to fabricate nanopores on top of pre-formed micron-pyramid silicon surface, called NPP structure. The equivalent medium layer with graded refractive index appeared on NPP textures makes the absorption of almost all incident light independent of the wavelength and angle. However, serious Auger recombination and surface recombination associated with NPP structure is detrimental to emitter passivation, usually counteracting the photocurrent gain. To identify an appropriate balance of light-trapping and surface passivation, we investigate the impact of different radio-frequency power (PRF) on the optical and electrical properties of TOPCon solar cells and discusses the underlying structural causes behind these observed improvements. Finally, we demonstrate NPP TOPCon solar cells with an average short-circuit current density of 41.44 mA/cm2 and an average PCE of 23.55% at the PRF of 600 W. Besides, the external quantum efficiency results under various incident angles from 0° to 70° exhibited excellent wide-angle spectral absorption capability, which is significant for solar cells working in an outdoor environment.

Blistering-free polycrystalline silicon carbide films for double-sided passivating contact solar cells

Polysilicon (poly-Si) passivating contacts have attracted considerable attentions in the academic community and photovoltaic industry due to their remarkable advantages of outstanding passivation quality and low contact resistivity. Plasma enhanced chemical vapor deposition (PECVD), as one of the widely adopted techniques to prepare doped poly-Si films, is usually limited by the occurrence of blistering, especially for boron-doped (B-doped) poly-Si films. In this work, we present a study of PECVD preparation of B-doped polycrystalline silicon carbide (poly-SiC x ) films with a blistering-free appearance by incorporating carbon (C) and optimizing the annealing process. It demonstrates that a thick poly-Si deposited on polished c-Si substrates with a low surface roughness tends to blister, which thus leads to a poor passivation performance. Moreover, the investigation of C content and annealing condition suggests that increasing C content or lowering incipient annealing temperature is beneficial to suppress the blistering. However, the C content needs to be well controlled to balance the passivation and contact properties, because the excessive CH 4 flow during the film deposition would degrade the contact performance with a high contact resistivity (>100 mΩ cm 2 ). Finally, the proof-of-concept devices featuring the double-sided passivating contacts (DPPCs) were fabricated with a front n-type poly-Si and rear p-type poly-SiC x , and presented an open-circuit voltage of 695 mV and an efficiency of 19.82%. The results clarify the correlation of C contents, c-Si substrate roughness and annealing process with the blistering levels and the passivation/contact properties, providing a valuable guidance for fabricating high-efficiency DPPC solar cells. • A path way to prepare blistering-free Boron-doped PECVD poly-Si films has been revealed. • A 90 nm thick PECVD prepared B-doped poly-Si film with a blistering-free appearance has been proposed. • A proof-of-concept double-sided poly-Si passivating contact solar cells with an efficiency of 19.82% has been presented.