Electrical Analysis of Pulsed Laser Annealed Poly-Si: Ga/SiOx Passivating Contacts
In this contribution, we examine Ga hyper-doped poly-Si/SiOx contacts realized by pulsed laser melting (PLM). Here, we use Ga as a novel p-type dopant and B as a conventional dopant to induce non-equilibrium doping using an excimer laser. We perform simulations to visualize the maximum melt depth profiles within the poly-Si, with a goal of distributing dopants close to the tunneling oxide, but at the same time preserving the passivation. Hall measurements show that sheet resistance for B is lower than Ga due to its higher solid solubility limit in Si. After comparing the Hall active dopant concentration with the chemical concentration obtained by SIMS measurement, we show nearly 100% activation B activation reaching 10^21 cm-3, while only ~20% activation for Ga. Nevertheless, we achieve active doping concentrations of Ga in poly-Si six times higher than its solid solubility limit in Si (~10^19 cm-3). We compare our Hall mobilities with values in the literature for c-Si and show that B mobilities in laser-treated poly-Si are close to that of the literature value for B, while Ga mobilities are lower, possibly due to additional scattering channels within grain boundaries and deformed lattice. We also compare our results on PLM samples with conventional furnace annealed samples, and we show much higher percent activation and mobilities. Previously, we showed a low contact resistivity of 35.5 +/- 2.4 m..omega..cm2. Here, we further confirm this result by scanning spreading resistance microscopy and Kelvin force nanoprobe microscopy. We demonstrate that our poly-Si: Ga/nCz contact exhibits large drift and diffusion currents under normal cell operating voltage, which widens the laser processing window for a good metal/poly-Si/c-Si contact.
- Research Organization:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1997376
- Report Number(s):
- NREL/CP-5K00-87324; MainId:88099; UUID:96e5a759-b83d-4b7d-b380-7feb1684f8fa; MainAdminID:70332
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electrical Analysis of Pulsed Laser Annealed Poly-Si:Ga/SiOx Passivating Contacts
Novel Poly-Si:Ga/SiOx Passivating Contacts through Non-Equilibrium Doping
Non-Equilibrium Doping of Poly-Si:Ga/SiOx Passivating Contacts Solar Cells
Conference
·
Mon Oct 17 00:00:00 EDT 2022
·
OSTI ID:1894481
Novel Poly-Si:Ga/SiOx Passivating Contacts through Non-Equilibrium Doping
Conference
·
Fri Sep 10 00:00:00 EDT 2021
·
OSTI ID:1968450
Non-Equilibrium Doping of Poly-Si:Ga/SiOx Passivating Contacts Solar Cells
Conference
·
Wed Aug 24 00:00:00 EDT 2022
·
OSTI ID:1889660