Simple experimental method for alpha particle range determination in lead iodide films

Dmitriev, Yuri; Bennett, Paul R.; Cirignano, L.; Klugerman, M.; Shah, K.S.

doi:10.1063/1.2741369

Cited by 11 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, the standard models of the effects of roughness on the contact angle (Wenzel, Cassie–Baxter, and pinning ) predict the opposite effect: roughness increases the value of the contact angle of hydrophobic surfaces. Another difference between the experimental samples and the atomistic ones is the absence of defects in the computational models, which, on the contrary, are typically found at surfaces of real semiconductors . To investigate this hypothesis, we have considered prototypical defected PbI 2 surfaces containing vacancies (see the Supporting Information for details).…”

Section: Resultsmentioning

confidence: 99%

Hydrophilicity and Water Contact Angle on Methylammonium Lead Iodide

Caddeo

Marongiu

Meloni

et al. 2018

Adv Materials Inter

View full text Add to dashboard Cite

and by relating its value to the liquidsurface adhesion: the larger the adhesion, the smaller the contact angle. [1] Contact angle measurements have become accordingly a powerful yet cheap technique to quantify the water interaction with solid surfaces, a problem of huge technological importance in fluid dynamics, [2] aerospace engineering, [3] biology, [4] surface chemistry, [5] textile, [6] and materials science. [7] In photovoltaics, the interaction of water with surfaces is of great importance for example for organic and hybrid solar cells that are sensitive to humid conditions. This is the case of methylammonium lead iodide (CH 3 NH 3 PbI 3 or MAPI) which is at the core of the nowadays most efficient hybrid-based solar technology (with 23% maximum power conversion efficiencies [8][9][10][11] ) and which has potential applications also in the fields of optoelectronics, [12,13] lasing, [14][15][16][17][18] photocatalysis, [19] and thermoelectricity. [20][21][22] The interaction of MAPI with water is a major concern for such technology as it drives degradation in humid air and full decomposition in liquid water. [23][24][25] Accordingly, there is an increasing number of research items focusing on increasing the hydrophobicity of MAPI via, e.g., surface functionalization. In this context, contact angle measurements have been performed on pristine and hydrophobized films to assess their wettability. [26][27][28] Measurements of the contact angle of water on hybrid perovskites and, more in general, on soluble or transforming surfaces is challenging. If the substrate degrades, several nonequilibrium phenomena must be taken into account such as the solubilization and phase transformations of the solid. This led to ambiguous results on MAPI, with a contact angle that strongly depends on the time of measurement, [26][27][28] calling for a detailed microscopic investigation at the origin of the variability of the measured CA.Here, we combine molecular dynamics (MD) simulations with millisecond contact angle-measurements. We show that finite temperature MD simulations can reproduce experimental contact angles of water in a good agreement with the Young-Dupré (YD) continuum relation between liquid-solid adhesion and contact angle, and we explain the high CA value measured for water on MAPI as the result of the interaction of water with degraded superficial layers at the water/perovskite interface.Surface properties are often assessed with measurements of the contact angle of a water drop. The process is however flawed for the very important class of hybrid perovskite materials, extensively employed in solar cells and optoelectronics research, because they are water soluble and their surface degrades during contact angle measurements. While hybrid perovskites are considered to be highly hydrophilic, a contact angle with water of 83° can be measured, as if they were almost hydrophobic. By combining experiments and simulations, the actual value is explained as the result of the interaction of water with degraded superficial...

show abstract

Section: Resultsmentioning

confidence: 99%

Hydrophilicity and Water Contact Angle on Methylammonium Lead Iodide

Caddeo

Marongiu

Meloni

et al. 2018

Adv Materials Inter

View full text Add to dashboard Cite

show abstract

“…The difference in shape and magnitude of the dark current for up-ramped and down-ramped voltage (hysteresis) is due to the domination of the one sign defect number. As was shown [11], the dominant surface defects in PbI 2 films are positive charged defects (positive adsorbates (Me+) and iodine vacancies (+) (Fig. 4)).…”

Section: Article In Pressmentioning

confidence: 90%

“…1a, b). These films have immense surface area [11] that can be bigger, as the simple estimations show, than surface area of CIPed (Fig. 1c) by up to 10 times.…”

Section: Methodsmentioning

confidence: 95%

“…All further experimental results and their interpretation relate only to as-grown PbI 2 films because CIP treatment [11] generates additional defects in PbI 2 films that completely change films' defect structure. Fig.…”

Section: Temperature Dependence Of Dark Currentmentioning

confidence: 95%

“…Two identical contacts responses' asymmetry is explained by non-uniformity of the film thickness and/or by usage of non-collimated X-ray source in these experiments. As was discussed [10,11], only the contact area must be irradiated since increasing irradiated film area over contact area leads to involving additional charge carriers to radiation-induced current.…”

Section: Article In Pressmentioning

confidence: 98%

See 2 more Smart Citations