Abstract Surface passivating thin films are crucial for limiting the electrical losses during charge carrier collection in silicon photovoltaic devices. Certain dielectric coatings of more than 10 nm provide excellent surface passivation, and ultra‐thin (<2 nm) layers can serve as interlayers contacts. Here, SiO 2 , Al O 3 HfO created via plasma‐enhanced atomic layer deposition annealing. It is found that negatively charged exhibit passivation properties—exceeding those —with 0.9 annealed...

Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving performance lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, role Si surface termination merits further consideration. Here, scanning electrochemical cell microscopy (SECCM) used a glovebox, followed by secondary ion mass spectrometry (SIMS) identical locations study local behavior...

Understanding surface passivation arising from aluminium oxide (Al2O3) films is of significant relevance for silicon-based solar cells and devices that require negligible recombination. This study aims to understand the competing bulk lifetime effects which occur during activation atomic layer deposited Al2O3. We demonstrate maximum achieved on n- p-type silicon with at ∼ 450 °C, irrespective annealing ambient. Upon stripping Al2O3 re-passivating using a superacid-based technique, we find...

We introduce a two-fluid mobility model incorporating fundamental aspects of electron-hole (e-h) scattering such as momentum conservation for simulating laser-driven semiconductor switches (LDSSs). Compared to previous works that use Matthiessen's rule, the predicts distinct AC responses e-h plasmas in semiconductors. Based on model, we develop theory with very few adjustable parameters switching performance LDSSs based high-purity indirect-gap semiconductors silicon (Si). As prototypical...

The integration of single-layer transition metal dichalcogenides (TMDCs) in nanoscale field-effect transistor devices requires the deposition a high dielectric constant (high-κ) material to act as gate dielectric. Traditional thermal atomic layer (ALD) is commonly used deposit dielectrics on three-dimensional substrates, but ALD high-κ materials monolayer TMDCs more challenging. Thermal with water (H2O) co-reactant often results incomplete and nonuniform growth atomically thin TMDCs, owing...

We have studied the mechanisms underpinning effective surface passivation of silicon with hafnium oxide (HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) thin films grown <italic xmlns:xlink="http://www.w3.org/1999/xlink">via</i> atomic layer deposition (ALD). Plasma-enhanced ALD O plasma and a tetrakis(dimethylamido)hafnium precursor was used to deposit 12 nm thick HfO at 200 °C on high-lifetime 5 Ωcm...

We investigate the potential of ultra-thin HfO2 films grown by atomic layer deposition for passivating contacts to silicon focusing on variations in film thickness and post-deposition annealing temperature. A peak passivation quality – as assessed carrier lifetime measurements is reported 2.2 nm thick annealed at 475 °C, which a surface recombination velocity <1 cm/s determined. For <2.2 thick, there marked decrease quality. X-ray diffraction highlights change from crystallised monoclinic...

Treatment with the superacid bis(trifluoromethanesulfonyl)amide (sometimes known as TFSA, TFSI, or HNTf2) enhances properties of a wide range optoelectronic materials, resulting in longer effective carrier lifetimes and higher photoluminescence quantum yields. We have conducted multimaterial study treating both crystalline silicon transition metal dichalcogenide (TMDC) monolayers few-layer flakes solutions formed from TFSA compounds related chemical structures different Lewis acidities,...

Minimizing electrical losses at metal/silicon interfaces in high-efficiency single-junction silicon solar cells requires the use of carrier-selective passivating contacts. The electronic barrier heights insulator/silicon interface are necessary for calculating probability quantum tunneling charge carriers these interfaces. Thus, precise knowledge parameters is crucial development contact schemes. Using a photoemission-based method, we experimentally determine band offsets Al <sub...

Optical pump terahertz probe spectroscopy (OPTP) is a versatile non-contact technique that measures transient photoconductance decays with femtosecond temporal resolution. However, its maximum range limited to only few nanoseconds by the mechanical delay lines used. We extended of OPTP milliseconds and longer while retaining sub-nanosecond A separate laser was electrically synchronized pulses, allowing pump–probe be controlled an electronic generator. demonstrated capabilities this examining...

Hafnium oxide thin films have attracted considerable interest for passivation layers, protective barriers, and anti-reflection coatings. This study presents a systematic investigation into the role of film growth co-reactant on properties.

Hafnium oxide (HfO x ) films grown by atomic layer deposition (ALD) have recently been demonstrated to provide high‐quality silicon surface passivation. Reports suggested that changing the composition of hafnium‐containing precursor can enable both charge polarities be produced. Herein, passivation quality hafnium with metal amide precursors and a tetrakis(ethylmethylamido)hafnium (TEMAHf) is examined, considering film polarity, chemical‐ field‐based effects, crystallinity. Throughout,...

Minimizing recombination at semiconductor surfaces is required for the accurate determination of bulk carrier lifetime. Proton donors, such as hydrofluoric acid and superacids, are well known to provide highly effective short-term surface passivation. We demonstrate here that aprotic solutions based on bis(trifluoromethanesulfonyl)methane (TFSM) in hexane or pentane can also result excellent passivation (100)-orientation silicon surfaces. show optimized TFSM-pentane scheme measure lifetimes...

Production of a temporally stable chemically enhanced ultra-thin HfO 2 interlayer with excellent passivation for use in photovoltaic passivating contacts.

Abstract Monolayer molybdenum disulfide (1L MoS 2 ), a promising optoelectronic material, emits strong visible photoluminescence (PL). Systematic control of the intensity, energy, and spectral width PL from 1L on silicon dioxide/silicon (SiO /Si) is demonstrated via simple external treatments. Treating with solutions formed superacid bis‐(trifluoromethanesulfonyl)amide (TFSA) enhances, blueshifts, sharpens PL. Treatments structurally analogous chemicals that lack sulfur, in case...

Photoexcited muon spin spectroscopy (photo-μSR) is used to study excess charge carrier lifetimes in silicon. Experiments are performed on silicon wafers with very high bulk the surface passivation conditions intentionally modified control effective lifetime. When lifetime low (&amp;lt;500 μs), implanting muons different depths enables reliable measurement of as a function distance from surface. It also demonstrated that photo-μSR technique can measure completed commercial gallium doped...

Subnanometer-scale silicon dioxide (SiO2) films are frequently present before, during, and after device processing, yet they offer minimal surface passivation can detrimentally impact subsequent processing steps. Here we develop a process whereby the of nanometer subnanometer SiO2 is enhanced by up to 2 orders magnitude simple room temperature treatment using superacid bis(trifluoromethane)sulfonimide (TFSA, sometimes TFSI). By accurately modeling effective lifetime curves corresponding...

The carrier lifetime stability of gallium-doped silicon wafers and performance industrial PERC solar cells produced from sister were investigated under four different illumination conditions temperatures. seven materials feature a resistivity variation 0.4–1.0 Ωcm samples processed to create high hydrogen content (with PECVD SiNx) or low ALD Al2O3 HfO2). Our results confirm that the material itself is prone light elevated temperature induced degradation (LeTID), however experiments on...

Muons are part of natural cosmic radiation but can also be generated at spallation sources for material science and particle physics applications. Recently, pulsed muons have been used to characterize the density free charge carriers in semiconductors their recombination lifetime. Muon beam irradiation result formation dilute levels crystal defects silicon. These only detected high carrier lifetime silicon samples that highly sensitive due long lifetimes. This work investigates...

Abstract Monolayer molybdenum disulfide (MoS 2 ) is a promising candidate for inclusion in optoelectronic technologies, owing to its two-dimensional (2D) nature and resultant novel photoluminescence (PL). Chemical vapour deposition (CVD) an important method the preparation of large-area films monolayer MoS . The PL character as-prepared must be well understood facilitate detailed evaluation any process-induced effects during device fabrication. We comparatively explore emission from four...