Co-diffusion of boron and phosphorus for ultra-thin crystalline silicon solar cells

Abstract

This paper reports the fabrication of crystalline silicon passivated emitter rear totally diffused (c-Si PERT) solar cells with ultra-thin p-type wafers 50 µm in thickness. Co-diffusion of boron and phosphorus in a single rapid thermal processing cycle, and an Al spin-on glass post-curing process were developed to remove the boron rich layer which is detrimental to c-Si solar cells. Co-diffusion was carried out with spin-on diffusion sources using boric acid and a P spin on dopant for simple and cost-effective emitter and back surface field (BSF) formation processes. The fabricated ultra-thin c-Si PERT cell featured an open circuit voltage (Voc) of 0.575 V, a short circuit current density (Jsc) of 35.8 mA cm−2, a fill factor of 0.725, and a power conversion efficiency of 15.0%. The efficiency has improved by 2% compared with the standard structure cell with Al-BSF using thin evaporated Al 2 µm in thickness. Along with cell output parameters, the flexural strength and critical bending radius were measured by a four point bending test, and the results showed that the solar cells with thinner rear Al electrodes are more applicable for a flexible solar cell device.

First Discovery of Vespa velutina nigrithorax du Buysson (Hymenoptera: Vespidae), an Invasive Hornet in the Feces of the Yellow-Throated Marten in South Korea

“…Approximately 3000 YTMs are currently estimated to inhabit South Korea [ 60 ]. YTMs are omnivorous and highly fluid, depending on the available food resources and the season [ 61 ].…”

Thermally Triggered Triazolinedione–Tyrosine Bioconjugation with Improved Chemo- and Site-Selectivity

“…The orthogonal nucleophilic reactivity of these residues allows their chemo-selective targeting, which also translates into siteselectivity due to their less frequent presence on protein surfaces. 34,35 Examples of tyrosine modification include Oalkylation through pi-allyl palladium complexes, 36 aniline coupling, 37 sulfur fluoride exchange (SuFEx), 38 rhodiumbased arene complexes, 39 Suzuki cross-couplings, 40 diazo coupling reactions, 41,42 Mannich-type reactions, 43 heminactivated luminol derivatives, 44,45 hypervalent iodines, 46 radical chemistry, 47 and photoredox catalysis. 48 Examples of tryptophan-specific bioconjugation strategies are less common, and perhaps also less generally useful, even though it often does allow site-specific modification in case a single exposed tryptophan residue is present in a given target.…”

Fluorosulfate as a Latent Sulfate in Peptides and Proteins

“…Fluorosulfate also remained mostly intact after 12 h in serum and after 48 h in cell lysate (Table S2). Even tetramethylguanidine, a reagent previously reported to promote SuFEx reaction in aqueous solution, 35 showed no reactivity against fluorosulfate alone (Table S1, Entry 3). Interestingly, we found the hydrolysis product of N-hydroxylsuccimide (Table S3 and Figure S2), Nhydroxylsuccinic acid monoamide (3), converted a fsYcontaining hexapeptide 1 into the corresponding sulfopepitde 2 in 57% yield in 1 h (Figure 2a).…”