730 mV implied Voc enabled by tunnel oxide passivated contact with PECVD grown and crystallized n+ polycrystalline Si

Tao, Yuguo; Chang, Elizabeth; Upadhyaya, Ajay; Roundaville, Brian; Ok, Young-Woo; Madani, Keeya; Chen, Chia-Wei; Tate, K.; Upadhyaya, Vijaykumar; Zimbardi, Francesco; Keane, J.; Payne, Adam; Rohatgi, A.

doi:10.1109/pvsc.2015.7356218

Cited by 5 publications

(6 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ex situ doping of the poly-Si layers is performed via ion implantation using a Varian EHP500 implanter. Phosphorous (P) and boron (B) are implanted, selecting an energy of 10 keV and 5 keV, respectively, with variable dose from 5Á10 15 to 1.2Á10 16 ions/cm 2 . Figure 1A,B sketches the symmetric samples fabricated in this work.…”

Section: Methodsmentioning

confidence: 99%

“…Sample n1, implanted at lower dose, exhibits relatively low performance with τ eff = 0.8 ms, J 0 = 72 fA/cm 2 , and iV OC = 664 mV. When implantation dose is increased up to 1Á10 16 ions/cm 2 (sample n2), lifetime increases up to 1.8 milliseconds, and J 0 decreases to 39 fA/cm 2 with improved iV OC up to 688 mV. The better passivation properties observed for increased implantation dose can be explained by the higher doping concentration into poly-Si layer that enhances carrier selectivity inducing a stronger electrical field across the junction.…”

Section: C-si Surface Passivation By Poly-si Selective Contactsmentioning

confidence: 99%

“…The layer implanted with a dose of 5Á10 15 ions/cm 2 exhibited the lowest τ eff (0.5 ms), with a poor behavior at low injection level. By increasing the dose up to 7.5Á10 15 and 1Á10 16 ions/cm 2 , the lifetime curves shift up in the entire injection level with a τ eff~2 ms. Further increasing the dose up to 1.2Á10 16 ions/cm 2 , τ eff degrades down to 0.5 milliseconds with a severe effect on the surface passivation (iV oc = 663 mV). In these cases, sheet resistance is varying from 310 Ω/sq (D = 5Á10 15 cm 2 ) to 200 Ω/sq (D = 10 16 cm 2 ).…”

Section: C-si Surface Passivation By Poly-si Selective Contactsmentioning

confidence: 99%

“…This is because the resulting junction is Auger-limited with a J 0 = 95 fA/cm 2 , according to a qualitative simulation run by EDNA 2. 62 The optimum for 75-nm-thick poly-Si layer is found indeed for a dose of 1Á1016 ions/cm 2 . In this case, J 0 = 14 fA/cm 2 and iV OC = 703 mV indicate a trade-off between optimal surface vs Auger recombination mechanisms.…”

mentioning

confidence: 91%

“…12 The transport principle at this junction may occur via tunneling 13,14 and/or via pin-holes present at c-Si/SiO 2 interface. 15 This passivation scheme has proved to give excellent passivation properties 16 with implied open-circuit voltage (iV OC ) obtained up to 730 mV and saturation current density (J 0 ) well below 10 fA/cm 2 . Moreover, as typical process temperatures are above approximately 900 C, such devices exhibit high thermal stability and are, in principle, compatible with conventional metallization techniques.…”

mentioning

confidence: 98%

See 4 more Smart Citations

Implantation‐based passivating contacts for crystalline silicon front/rear contacted solar cells

Limodio

Yang

Groot

et al. 2020

Progress in Photovoltaics

View full text Add to dashboard Cite

In this work, we develop SiOx/poly‐Si carrier‐selective contacts grown by low‐pressure chemical vapor deposition and boron or phosphorus doped by ion implantation. We investigate their passivation properties on symmetric structures while varying the thickness of poly‐Si in a wide range (20‐250 nm). Dose and energy of implantation as well as temperature and time of annealing were optimized, achieving implied open‐circuit voltage well above 700 mV for electron‐selective contacts regardless the poly‐Si layer thickness. In case of hole‐selective contacts, the passivation quality decreases by thinning the poly‐Si layer. For both poly‐Si doping types, forming gas annealing helps to augment the passivation quality. The optimized doped poly‐Si layers are then implemented in c‐Si solar cells featuring SiO2/poly‐Si contacts with different polarities on both front and rear sides in a lean manufacturing process free from transparent conductive oxide (TCO). At cell level, open‐circuit voltage degrades when thinner p‐type poly‐Si layer is employed, while a consistent gain in short circuit current is measured when front poly‐Si thickness is thinned down from 250 to 35 nm (up to +4 mA/cm2). We circumvent this limitation by decoupling front and rear layer thickness obtaining, on one hand, reasonably high current (JSC‐EQE = 38.2 mA/cm2) and, on the other hand, relatively high VOC of approximately 690 mV. The best TCO‐free device using Ti‐seeded Cu‐plated front contact exhibits a fill factor of 75.2% and conversion efficiency of 19.6%.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: C-si Surface Passivation By Poly-si Selective Contactsmentioning

confidence: 99%

Section: C-si Surface Passivation By Poly-si Selective Contactsmentioning

confidence: 99%

mentioning

confidence: 91%

mentioning

confidence: 98%

See 3 more Smart Citations

Implantation‐based passivating contacts for crystalline silicon front/rear contacted solar cells

Limodio

Yang

Groot

et al. 2020

Progress in Photovoltaics

View full text Add to dashboard Cite

show abstract

Replacing the amorphous silicon thin layer with microcrystalline silicon thin layer in TOPCon solar cells

Tao

Sun

et al. 2016

Solar Energy

View full text Add to dashboard Cite

Structure and electrical properties of polysilicon films doped with ammonium tetraborate tetrahydrate

Tang,

Wang,

Zhou

et al. 2024

J. Semicond.

View full text Add to dashboard Cite

Here, p-type polysilicon films are fabricated by ex-situ doping method with ammonium tetraborate tetrahydrate (ATT) as the boron source, named ATT-pPoly. The effects of ATT on the properties of polysilicon films are comprehensively analyzed. The Raman spectra reveal that the ATT-pPoly film is composed of grain boundary and crystalline regions. The preferred orientation is the (111) direction. The grain size increases from 16−23 nm to 21−47 nm, by ~70% on average. Comparing with other reported films, Hall measurements reveal that the ATT-pPoly film has a higher carrier concentration (>1020 cm−3) and higher carrier mobility (>30 cm2/(V·s)). The superior properties of the ATT-pPoly film are attributed to the heavy doping and improved grain size. Heavy doping property is proved by the mean sheet resistance (R sheet,m) and distribution profile. The R sheet,m decreases by more than 30%, and it can be further decreased by 90% if the annealing temperature or duration is increased. The boron concentration of ATT-pPoly film annealed at 950 °C for 45 min is ~3 × 1020 cm−3, and the distribution is nearly the same, except near the surface. Besides, the standard deviation coefficient (σ) of R sheet,m is less than 5.0%, which verifies the excellent uniformity of ATT-pPoly film.

show abstract

730 mV implied Voc enabled by tunnel oxide passivated contact with PECVD grown and crystallized n+ polycrystalline Si

Cited by 5 publications

References 17 publications

Implantation‐based passivating contacts for crystalline silicon front/rear contacted solar cells

Implantation‐based passivating contacts for crystalline silicon front/rear contacted solar cells

Replacing the amorphous silicon thin layer with microcrystalline silicon thin layer in TOPCon solar cells

Structure and electrical properties of polysilicon films doped with ammonium tetraborate tetrahydrate

Contact Info

Product

Resources

About