Gurleen Kaur

Hybrid hole transport layers (HHTLs) consisting of‐a low‐cost, low‐temperature, dopant‐free, organic, hole‐selective poly(3,4‐ethylenedioxythiophene):polystyrene sulphonate (PEDOT:PSS) and an inorganic homogenous tunnel oxides (HoTOs), such as SiO_x, TiO_x, and AlO_x have allowed significant improvements in carrier selectivity as well as in power and cost efficiency. These key parameters can be further improved by introducing heterogeneous tunnel oxides (HeTOs), formed of two different inorganic oxides. This work examines the potential of heterogeneous HHTLs and their impact on passivation as well as on the interfacial properties in silicon solar cells. HeTOs of SiO_x/TiO_x and SiO_x/AlO_x with negative fixed charge are studied and optimized. A heterogeneous HHTL with AlO_x (>1.5 nm) resulted in a high lifetime (1.2 ms), low surface recombination velocity, and improved surface band bending at the interface due to the presence of higher negative fixed charge (10¹² cm⁻²) within these layers. The passivation properties further improved on light soaking and annealing due to oxidation of PSS and AlO_x/SiO_x. Overall, these HHTLs demonstrated a hole selectivity (S₁₀) of 12.5 and very high efficiencies up to of 26.1%, surpassing homogenous‐SiO_x/PEDOT:PSS by 1.4%.

Nanocrystalline silicon oxide (nc-SiOx:H) is a multipurpose material with varied applications in solar cells as a transparent front contact, intermediate reflector, back reflector layer, and even tunnel layer for passivating contacts, owing to the easy tailoring of its optical properties. In this work, we systematically investigate the influence of the gas mixture (SiH₄, CO₂, PH₃, and H₂), RF power, and process pressure on the optical, structural, and passivation properties of thin n-type nc-SiOx:H films prepared in an industrial, high-throughput, plasma-enhanced chemical vapor deposition (PECVD) reactor. We provide a detailed description of the n-type nc-SiOx:H material development using various structural and optical characterization techniques (scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Raman spectroscopy, and spectroscopic ellipsometry) with a focus on the relationship between the material properties and the passivation they provide to n-type c-Si wafers characterized by their effective carrier lifetime (τ_eff). Furthermore, we also outline the parameters to be kept in mind while developing different n-type nc-SiOx:H layers for different solar cell applications. We report a tunable optical gap (1.8–2.3 eV) for our n-type nc-SiOx:H films as well as excellent passivation properties with a τ_eff of up to 4.1 ms (implied open-circuit voltage (iV_oc)~715 mV) before annealing. Oxygen content plays an important role in determining the crystallinity and hence passivation quality of the deposited nanocrystalline silicon oxide films.

Nanocrystalline silicon oxide (nc-SiOx:H) is a multipurpose material with its varied application in solar cells as a transparent front contact, intermediate reflector, back reflector layer and even tunnel layer for passivating contacts, owing to easy tailoring of its optical properties. In this work, we systematically investigate the influence of gas mixture (SiH4, CO2, PH3 and H2), RF power and process pressure on the optical, structural and passivation properties of thin n-type nc-SiOx:H films prepared in an industrial, high throughput, plasma-enhanced chemical vapor deposition (PECVD) reactor. We provide a detailed description of the n-type nc-SiOx:H material develop-ment using various characterization techniques (SEM, EDX, Raman spectroscopy, and spectro-scopic ellipsometry) with a focus on the relationship between the material properties and the pas-sivation they provide to n-type c-Si wafers characterized by their effective carrier lifetime (τeff). Further, we also outline the parameters to be kept in mind while developing different n-type nc-SiOx:H layers for different solar cell applications. We report a tunable optical gap (1.8 – 2.3 eV) for our n-type nc-SiOx:H films as well as excellent passivation properties with τeff up to 3.5 ms (iVoc ~ 715 mV) before annealing. Oxygen content plays an important role in determining the crystallinity and hence passivation quality of the deposited nanocrystalline silicon oxide films.

Objective: This study aims to comprehend the current state of integration between artificial intelligence (AI) and the human resources (HR) sector. Specifically, it investigates the implementation of AI in HR, explores the challenges associated with this integration, and examines potential hazards related to data usage, AI's perceived gimmickry, and algorithmic governance. Method: Employing a descriptive research design, this study relies on secondary data as no primary research was conducted. Information was collected from research papers, books, websites, blogs on human resources, and survey reports released by various research groups. Results: The analysis reveals that AI's adoption in the HR sector is still in its early stages despite significant advancements made by start-ups. Challenges stem from various factors, including data complexities, the risk of AI being seen as a mere gimmick, and concerns about algorithmic governance. The multifaceted nature of AI introduces diverse approaches and applications, from algorithms to deep learning and natural language processing. The study also differentiates between strong AI (general intelligence) and weak AI (problem-specific intelligence). The study emphasizes that HR is a pivotal element of any business, directly impacting employee well-being, communication, and productivity. The integration of AI has brought notable improvements by automating low-value HR tasks, freeing resources for strategic work. AI's capacity to analyze vast data volumes rapidly promises enhanced employee experiences across talent management and recruitment. Conclusions: In conclusion, AI's integration into the HR sector is still evolving, with both promise and challenges. The study underscores the need for addressing the complexities of data utilization, avoiding AI's reduction to mere gimmickry, and establishing responsible algorithmic governance. By understanding the nuances of AI integration in HR, organizations can leverage its potential to enhance productivity, communication, and employee experiences.

This work experimentally determines if a high interface charge in the tunnel layer can enhance the carrier selectivity of a passivated contact and thus the efficiency potential of a solar cell deploying such a contact on its rear-side. Tunnel layers with high interface charge density - (a) LPCVD-SiN _x for high positive charge and (b) ALD-AlO _x for high negative charge were optimized and deployed in a passivated contact structure (tunnel-layer/doped-poly-Si-capping-layer) to enhance (i) electron or (ii) hole selectivity, respectively. Subsequently, by measuring the total contact induced recombination (J _0,contact ) and the effective contact resistivity ( ρcontact), the selectivity and the efficiency potential according to Brendel's model was calculated. For electron selective passivated contacts, the efficiency potential of a solar cell, deploying a positive charged LPCVD-SiN _x tunnel layer was proven to be higher by 1% absolute, as compared to using a conventional SiO _x tunnel layer. However, for hole selective passivated contacts deploying a negative charged ALD-AlO _x tunnel layer, this was not observed, due to boron in-diffusion and associated charge compensation.

This work explores the possibility of using ultrathin silicon nitride (SiN x ) films with high positive fixed charge in a SiN x /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 SiN x films. Our preliminary experiments reveal excellent surface passivation and low recombination current density, J o (45 fA.cm ^-2 ) by ~1.5 nm thick LPCVD SiN x 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 SiN x films were further integrated into SiN x /n+poly-Si contacts and characterized for J o,contact and tunneling resistance, ρ contact . The best SiN x /n+poly-Si passivated contact in this study has J o, contact = 5.9 fA.cm ^-2 , ρ contact = 0.525 Ω.cm ² and an efficiency potential > 22.75%. According to our knowledge, it is the first report confirming the formation of passivated contacts with SiN x as the dielectric tunnel layer.