Parallelized Nanopillar Perovskites for Semitransparent Solar Cells Using an Anodized Aluminum Oxide Scaffold

Abstract

fi ber-shaped, [ 8 ] wearable, [ 9 ] and even semitransparent [ 10,11 ] perovskite solar cells.In particular, semitransparent solar cells are of great interest for future applications, such as power-generating window panels in buildings or automobiles, which would raise the usage ratio of solar energy without occupying additional space. [ 12,13 ] For example, building-integrated solar cells could lead to the creation of completely self-sustaining, pollution-free buildings. Furthermore, semitransparent solar cells can be stacked in a tandem device architecture in which a cell with a higher bandgap is placed atop another with a lower bandgap. [14][15][16] To date, most demonstrated semitransparent solar cells have been based on high-bandgap absorbers, thin polymers, and amorphous silicon absorbers, which result in critical losses in overall effi ciency. Perovskitebased absorbers possess outstanding lightabsorbing characteristics, and the explicit tradeoff between PCE and transparency can be adjusted by varying the thickness of the absorbing layer. In this strategy, the conventional approach is to form perovskite layers thin enough to attain the desirable high transparency. [17][18][19][20][21][22][23] Uniform, thin perovskite fi lms have been produced via evaporation or gasassisted spin-coating techniques. Roldán-Carmona et al. fabricated semitransparent perovskite solar cells by employing an evaporated 280 nm thick perovskite absorber layer, achieving a PCE of 7.73% and an average visible transmittance (AVT) of 19%. [ 10 ] Additionally, centimeter-scale, 135 nm thick evaporated CH 3 NH 3 PbI 3 thin fi lms were reported to have PCEs of 9.9%. [ 18 ] Using a gas-assisted spin-coating process, continuous 107 nm thick CH 3 NH 3 PbI 3 thin fi lms were demonstrated with PCEs of 8.1% and AVTs of 19%. [ 24 ] Along with the development of thin perovskite absorber layers, strategies for enhancing the carrier collection effi ciency, including the use of Ag nanowire electrodes, [ 20 ] graphene electrodes, [ 17 ] and atomically thin ZnO cathode buffer layers and Al 2 O 3 capping layers, [ 21 ] have been suggested to compensate for the limited light absorption.Despite the success of these approaches, the practical fabrication of large-scale continuous, thin perovskite fi lms remains challenging, and issues preventing commercial viability, including reproducibility and stability, are unresolved. Obtaining a highly effi cient, moderately thick absorber layer with a restricted open aperture is a prerequisite for achieving practical semitransparent photovoltaic devices. Two suggested Semitransparent solar cells have attracted signifi cant attention for practical applications, such as windows in buildings and automobiles. Here, semitransparent, highly effi cient, 1D nanostructured perovskite solar cells are demonstrated employing anodized aluminum oxide (AAO) as a scaffold layer. The parallel nanopillars in the perovskite layer enable construction of hazefree semitransparent devices without any hysteresis behavior. By controlling the...

Strain‐Mediated Phase Stabilization: A New Strategy for Ultrastable α‐CsPbI3 Perovskite by Nanoconfined Growth

“…This peak shift implies the completely pure α‐phase without any impurity as well as the reduced interfacial defect‐related traps . The lower trap density has been similarly observed when MAPbI 3‐ x Cl x was grown inside AAO scaffolds . The TRPL of the CsPbI 3 grown inside 30, 41, and 112 nm pore AAO templates was also measured (Figure b), and the carrier lifetimes of CsPbI 3 were determined as 136.7, 169.7, and 65.2 ns, respectively.…”

“…To investigate the effect of nanoconfinement induced by nanoporous AAO templates on phase stabilization, we first fabricated AAO templates with different pore sizes through the anodizing/widening steps of aluminum (Al) films deposited on top of blocking TiO 2 (bl‐TiO 2 )/fluorine‐doped tin oxide (FTO)/glass substrates (see the Experimental Section). The reference pore size was set to about 100 nm and various AAO templates with varying pore sizes smaller than 100 nm were prepared by controlling the anodization conditions (Figure S1, Supporting Information) . The evolution of cylindrical straight pores perpendicular to bl‐TiO 2 /FTO/glass substrate was confirmed in a cross‐sectional scanning electron microscopy (SEM) image for the 600 nm thick AAO template (Figure S2, Supporting Information).…”

“…Because the overlayer grown on top of the AAO template will not be subject to nanopore confinement, it is necessary to prevent the formation of such a perovskite overlayer to precisely investigate the effect of nanoscale confinement on phase stability. Thus, the filling levels of perovskite layers were controlled by adjusting the concentration of precursor solution and the revolutions per minute (rpm) during the spin‐infiltration, so that the CsPbI 3 layer should be spatially restricted only inside the pores of the AAO templates …”

Metal‐Nanowire‐Electrode‐Based Perovskite Solar Cells: Challenging Issues and New Opportunities

“…[102][103][104][105][106] However, in this approach, the vacuum deposition process is indispensably required for preparing thin metal films and the presence of metallic layers causes inevitable decreases in transmittance. [101] Therefore, a variety of top electrodes including AZO, [107] ITO, [108][109][110] In 2 O 3 :H, [111] PEDOT:PSS, [112,113] graphene, [114] CNT, [115] and MeNWs [87][88][89][91][92][93][94][95]97,[116][117][118][119] have been investigated for fabricating high-performance semi-transparent PSCs. When they are compared in the plot presenting the interdependency between AVT and PCE (Figure 3), it can be noticed that the semi-transparent cells employing AgNW-network top electrodes are in the top-right area, where highly transparent and high-functioning cells are positioned.…”

Patterned Perovskites for Optoelectronic Applications

“…This is because the PAM template inhibited the generation of the intrinsic ionic defects and blocked the erosion of moisture, resulting in long‐term stability of the device. Furthermore, with the help of a PAM, long‐term‐stable semitransparent solar cells (fluorine‐doped tin oxide (FTO)/compact‐TiO 2 /PAM+perovskite/spiro‐OMeTAD/MoO x /indium tin oxide (ITO)) were successfully achieved, which yielded a respectable measured PCE of 9.6% and 33.4% AVT (whole device) . It is noteworthy that the parameters of the PAM could act as balancer between the PCE and AVT to obtain optimal semitransparent perovskite solar cells.…”