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Back side p+ emitter thin silicon solar cells have been constructed using vapor phase epitaxy. Double porous structure on a c-Si substrate was used as a seed substrate in order to enable active layer separation after vapor phase epitaxy growth. Structure of the back side emitter solar cell was obtained in situ during the epitaxy process. In order to enhance solar cell response to light from a range of 700–1200 nm wavelength, the back side dielectric mirror was developed and optimized by means of a computer simulation and deposited by plasma enhanced chemical vapor deposition. At the same time, a reference sample was fabricated. Comparison of solar cells performance with or without the back side mirror was performed and clearly shows that the quality of solar light conversion into the electricity by means of solar cells, can be improved by using the structure proposed in this article. [ABSTRACT FROM AUTHOR]

To further increase the efficiency of thin film solar cells, it is critical to enhance the absorption over the full spectral wavelength range in which solar cells generate electricity. In this letter, we present a fullband absorption enhancement method for n-i-p thin film silicon solar cells based on a Quasi-Crystal Structure (QCS) by superimposing Ag random nanotextures on periodically patterned Micro-Cone Substrates. Both light in-coupling and light trapping abilities are significantly improved thanks to the reduction of front-surface reflection originated from the gradually changed refractive index of preserved micro-cone profile after film deposition and the richer guided mode resonances caused by the QCS. An initial efficiency of 10.4% is obtained for QCS-based hydrogenated amorphous silicon germanium (a-SiGe:H) solar cells, which outperforms the planar (efficiency of 7.5%) and randomly nanotextured (efficiency of 8.7%) counter part by 38.7% and 19.5%, respectively. The QCS can also be duplicated for other thin film photovoltaic devices and provides a new approach for creating high-efficiency thin-film solar cells. [ABSTRACT FROM AUTHOR]

We present a self-organizedmethod based on defocused ion beamsputtering for nanostructuring glass substrates which feature antireflective and light trapping effects. By irradiating the substrate, capped with a thin gold (Au) film, a self-organized Au nanowire stencil mask is firstly created. The morphology of the mask is then transferred to the glass surface by further irradiating the substrate, finally producing high aspect ratio, uniaxial ripple-like nanostructures whose morphological parameters can be tailored by varying the ion fluence. The effect of a Ti adhesion layer, interposed between glass and Au with the role of inhibiting nanowire dewetting, has also been investigated in order to achieve an improved morphological tunability of the templates. Morphological and optical characterization have been carried out, revealing remarkable light trapping performance for the largest ion fluences. The photon harvesting capability of the nanostructured glass has been tested for different preparation conditions by fabricating thin film amorphous Si solar cells. The comparison of devices grown on textured and flat substrates reveals a relative increase of the short circuit current up to 25%. However, a detrimental impact on the electrical performance is observed with the rougher morphologies endowed with steep v-shaped grooves. We finally demonstrate that post-growth ion beam restructuring of the glass template represents a viable approach toward improved electrical performance. [ABSTRACT FROM AUTHOR]

Thin film silicon solar cells are the better choice due to their low cost as compared to the crystalline solar cells. However, thin film silicon solar cells are suffering from a problem of weak absorption of incident light and hence, light trapping mechanism is essential for the harvesting of maximum solar radiation. In this paper, we present the performance of solar cell using an efficient back reflector composed of multilayer thin film (SiO 2 /Si 3 N 4 ) and a diffraction grating. The use of a back reflector showed enhanced light absorption due to the folding of unabsorbed light coming to it after crossing the active region in a wide wavelength range. Further, the effect of active layer thickness and grating height were also discussed for the optimal performance of the solar cell. In the case of magnetic transverse mode, a relative enhancement in cell efficiency about 79 and 21% respectively have been observed with respect to a planar and SC4 solar cells. [ABSTRACT FROM AUTHOR]

We present a self-organized method based on defocused ion beam sputtering for nanostructuring glass substrates which feature antireflective and light trapping effects. By irradiating the substrate, capped with a thin gold (Au) film, a self-organized Au nanowire stencil mask is firstly created. The morphology of the mask is then transferred to the glass surface by further irradiating the substrate, finally producing high aspect ratio, uniaxial ripple-like nanostructures whose morphological parameters can be tailored by varying the ion fluence. The effect of a Ti adhesion layer, interposed between glass and Au with the role of inhibiting nanowire dewetting, has also been investigated in order to achieve an improved morphological tunability of the templates. Morphological and optical characterization have been carried out, revealing remarkable light trapping performance for the largest ion fluences. The photon harvesting capability of the nanostructured glass has been tested for different preparation conditions by fabricating thin film amorphous Si solar cells. The comparison of devices grown on textured and flat substrates reveals a relative increase of the short circuit current up to 25%. However, a detrimental impact on the electrical performance is observed with the rougher morphologies endowed with steep v-shaped grooves. We finally demonstrate that post-growth ion beam restructuring of the glass template represents a viable approach toward improved electrical performance.

In this paper, we present a novel way of texturing glass facilitated by ZnO:Al thin film as sacrificial layer for thin film silicon solar cell application. We name this technique zinc oxide-induced texturing (ZIT). The texturing of glass was achieved by wet etching of ZnO:Al covered glass with HF and HNO3 as etchants. We investigated the influence of the ZnO:Al layer sputtering condition, the layer thickness, and the etchant composition on the surface morphology of the textured glass. We demonstrate that we are able to control the roughness of the ZIT glass over a wide roughness range, ranging from 20 to 400 nm. Highly efficient microcrystalline silicon n-i-p solar cells were deposited on ZIT glass. The influence of the substrate morphology on the solar cell performance is also discussed. The highest efficiency for a single junction n-i-p microcrystalline silicon solar cell obtained in this work is 10.64% (Active area). Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Optical and electrical simulations were carried out for thin film silicon solar tandem cells with intermediate reflector layer (IRL) between top and bottom cell and compared with experimental external quantum efficiency and current voltage characteristics results. Reference data were collected from a series of tandem cells with different thicknesses of the top cell absorber layer (160-240 nm), the bottom cell absorber layer (1750-2100 nm), and the transparent conductive oxides based IRL (10-80 nm). It turned out that for capturing correctly the influence of the IRL on the light management as a function of the IRL thickness, the conventional semicoherent approach is not sufficient. Whereas the optical properties of a very thin IRL are governed by interference effects that are best calculated using a fully coherent model, increasingly thicker IRL show a more and more incoherent behavior. By taking into account, the interface morphology and angular light distribution within the cell stack an algorithm for the effective IRL reflectivity was proposed that explains the experimental findings very well. The consecutive electrical simulations were carried out with the device simulator ASA. The dependence of short circuit current density jsc and fill factor FF on the thickness dIRL of the IRL is in qualitative agreement between simulation and experiment showing coincident extrema in jsc( dIRL) and FF( dIRL) at the current matching point. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We report on the hydrothermal growth of high quality arrays of single crystalline zinc oxide (ZnO) nanocolumns, oriented perpendicularly to the transparent conductive oxide substrate. In order to obtain precisely defined spacing and arrangement of ZnO nanocolumns over an area up to 0.5cm2, we used electron beam lithography. Vertically aligned ZnO (multicrystalline or single crystals) nanocolumns were grown in an aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine at 95°C, with a growth rate 0.5÷1μm/h. The morphology of the nanostructures was visualized by scanning electron microscopy. Such nanostructured ZnO films were used as a substrate for the recently developed 3-dimensional thin film silicon (amorphous, microcrystalline) solar cell, with a high efficiency potential. The photoelectrical and optical properties of the ZnO nanocolumns and the silicon absorber layers of these type nanostructured solar cells were investigated in details. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we investigate tandem amorphous/microcrystalline silicon solar cells with asymmetric intermediate reflectors grown in the n–i–p substrate configuration. We compare different types of substrates with respect to their light-trapping properties as well as their influence on the growth of single-junction microcrystalline cells. Our most promising back reflector combines a textured zinc oxide film grown by low-pressure chemical vapor deposition, a silver film for reflection, and a zinc oxide buffer layer. Grown on this substrate, microcrystalline cells exhibit excellent response in the infrared while keeping high open-circuit voltage and fill factor, leading to efficiencies of up to 10.0%. After optimizing the morphology of the asymmetric intermediate reflector, we achieve an n–i–p micromorph solar cell stabilized efficiency of 11.6%, using 270nm and 1.7μm of silicon for the absorber layer of the amorphous top cell and the microcrystalline bottom cell, respectively. Using this original device architecture, we reach efficiencies close to those of state-of-the-art n–i–p and p–i–n micromorph devices, demonstrating a promising route to deposit high-efficiency thin-film silicon solar cells on opaque substrates. [Copyright &y& Elsevier]

Abstract: Boron doped zinc oxide (ZnO:B) films with different thicknesses were prepared with low pressure chemical vapor deposition (LPCVD) technique and implemented in thin film silicon solar cells as front and back electrodes. It is found that thick back ZnO:B film electrode in thin film silicon solar cells leads to a high fill factors (FF), which is attributed to an improvement of the electrical properties of the thick ZnO:B films, and in the meanwhile a slightly low short circuit currents (J sc) due to a high light absorption in the thick back ZnO:B films. Differently, the thicker front ZnO:B film electrodes result in a high J sc but a low FF of solar cells compared to the thinner ones. The low FF of the solar cells may be caused by the local shunt originated from the pinholes or by the cracks (zones of non-dense material) formed in particular in microcrystalline silicon materials deposited on rough front ZnO:B films. As to the high J sc, it is expected to be due to a good light trapping effect inside solar cells grown on rough front ZnO:B films. Moreover, the application of high reflective polyvinyl butyral (PVB) foils effectively enhances the utilization of incident light in solar cells. By optimizing deposition process of the ZnO:B films, high efficiencies of 8.8% and 10% for single junction thin film amorphous silicon solar cells (a-Si:H, intrinsic layer thickness<200nm) and amorphous/microcrystalline silicon tandem solar cells (a-Si:H/μc-Si:H, intrinsic amorphous silicon layer thickness<220nm), respectively, are achieved. [Copyright &y& Elsevier]

Abstract: We report on the development and application of n-type hydrogenated microcrystalline silicon oxide (μc-SiOx:H) alloys in single and tandem junction thin film silicon solar cells. Single junction microcrystalline silicon (μc-Si:H) solar cells are prepared in n-i-p deposition sequence where n-type μc-SiOx:H films serve as window layers. In tandem solar cells, μc-SiOx:H layers are placed between amorphous (a-Si:H) and μc-Si:H component cells, serving as an intermediate reflector. The requirements for μc-SiOx:H layer depending on its application are discussed. Our results show that the optical, electrical and structural properties of μc-SiOx:H can be conveniently tuned over a wide range to fulfil various requirements for applications in both types of cells. Additionally, the properties of μc-SiOx:H layers appear to be substrate dependent, which should be taken into account when layers are utilized in cells. The advantages of low refractive index and high optical band gap allow to achieve high efficiencies of 9.2% and 12.6% for single junction and tandem solar cells, respectively. [Copyright &y& Elsevier]

Abstract: Texture etched zinc oxide is often used as transparent front contact for silicon thin film solar cells. Reactive sputtering is a potentially low-cost process. However, process stability, film uniformity, and reproducibility are challenges to be solved. Oscillations of the control signal and subsequent reaction of the plasma emission control with moving substrates from rotatable metallic targets cause fluctuations of aluminum doped zinc oxide (ZnO:Al) properties. Solutions to overcome such variations during the reactive sputtering process are discussed. However, effects on film properties, especially on etching behavior, cannot be totally removed. To achieve good light scattering properties for solar cell application ZnO:Al films are usually etched in dilute hydrochloric acid. An etch process based on hydrofluoric acid has been developed to tune the surface texture for a given ZnO:Al material. One feature of this process is the relaxed requirement on ZnO:Al film properties as the reactively sputtered ZnO:Al films do not necessarily possess optimized film structure for the HCl etch. Solar cells with optimized ZnO:Al front contacts achieved conversion efficiency well above 11%. [Copyright &y& Elsevier]

Abstract: High reflectivity is essential when a metal is used as back contact and reflector in thin-film silicon solar cells. We show that thermal annealing at 150°C improves the reflectivity of silver films deposited by sputtering at room temperature on nanotextured substrates. The annealing provokes two interlinked effects: rearrangement of the silver layer with a modification of its morphology and an increase of up to 42% in the grain size of the polycrystalline film for the preferential orientation as measured by X-ray diffraction. The main consequence of these two mechanisms is a large increase in the reflectivity of silver when measured in air. This reflectivity increase is also noticeable in devices: amorphous silicon thin-film solar cells grown on annealed silver films yield higher internal and external quantum efficiencies compared to cells grown on as-deposited silver. The morphology modification smoothes down the substrate, which is revealed by a clear increase of the open-circuit voltage and fill factor of the cells grown on top. An amorphous silicon cell with a 200nm nominally thick i-layer fabricated on a flexible plastic substrate yielded an initial efficiency close to 10% with 15.9mA/cm2 of short-circuit current using highly reflective annealed textured silver. We also propose, for industrial purpose, the sputtering of thin silver layer (120nm) under moderate substrate temperature (∼150°C) to increase the layer reflectivity, which avoids lengthening of the back reflector fabrication. [Copyright &y& Elsevier]

Abstract: The light trapping characteristics in the wavelength range of 0.5−1.2μm for the random back-reflective silicon film with omnidirectional top anti-reflection are numerically analyzed based on the simplified probability method. The spectrum averaged maximum external quantum efficiency (EQE) for the 5μm thick silicon film is evaluated with an increase of 10.6% compared with the best bulk planar silicon solar cell—suggesting that an efficiency higher than those of the best bulk planar cell can be obtained for thin film silicon solar cells several microns thick. The light absorption curves drop slowly with increased back absorption, exhibiting that the performance of the thin film silicon solar cell with light trapping is tolerant of back absorption. [Copyright &y& Elsevier]

Abstract: This paper presents the fabrication of thin film crystalline silicon solar cells on foreign substrates like alumina, glass–ceramic (GC) and metallic foils (ferritic steel—FS) using seed layer approach, which employs aluminium induced crystallisation (AIC) of amorphous silicon. Effect of hydrogen content in a-Si:H precursor films on the AIC process has been studied and the results showed that defects in the AIC grown films increased with increase of hydrogen content. At the optimal thermal annealing conditions, the AIC grown poly-Si films showed an average grain size of 7.6, 26, and 8.1μm for the films synthesised on alumina, GC, and FS, respectively. The grains were (100) oriented with a sharp Raman peak around 520cm−1. Similarly, n-type seed layers were also fabricated by over-doping of as-grown AIC layers using a highly phosphorus doped glass solution. The resistivity of as-grown films reduced from 8.4×10−2 Ωcm (p-type) to 4.1×10−4 Ωcm (n-type) after phosphorus diffusion. These seed layers of n-type/p-type were thickened to form an absorber layer by vapour phase epitaxy or solid phase epitaxy. The passivation step was applied before the heterojunction formation, while it was after in the case of homojunction. Open circuit voltage of the junctions showed a strong dependence on the hydrogenation temperature and microwave (μW) power of electron cyclotron resonance (ECR) plasma of hydrogen. Effective passivation was achieved at a μW power of 650W and hydrogenation temperature of 400°C. Higher values of solar conversion efficiencies of 5% and 2.9% were achieved for the n-type and p-type heterojunction cells, respectively fabricated on alumina substrates. The analysis of the results and limiting factors are discussed in detail. [Copyright &y& Elsevier]

Abstract: Mid-frequency magnetron sputtering of aluminum doped zinc oxide films (ZnO:Al) from tube ceramic targets has been investigated for silicon based thin film solar cell applications. The influence of working pressure on structural, electrical, and optical properties of sputtered ZnO:Al films was studied. ZnO:Al thin films with a minimum resistivity of 3.4×10− 4 Ωcm, high mobility of 50cm²/Vs, and high optical transmission close to 90% in visible spectrum region were achieved. The surface texture of ZnO:Al films after a chemical etching step was investigated. A gradual increase in feature sizes (diameter and depth) was observed with increasing sputter pressure. Silicon based thin film solar cells were prepared using the etched ZnO:Al films as front contacts. Energy conversion efficiencies of up to 10.2% were obtained for amorphous/microcrystalline silicon tandem solar cells. [Copyright &y& Elsevier]

Abstract: Conductive zinc oxide (ZnO) grown by low pressure chemical vapor deposition (LPCVD) technique possesses a rough surface that induces an efficient light scattering in thin film silicon (TF Si) solar cells, which makes this TCO an ideal candidate for contacting such devices. IMT-EPFL has developed an in-house LPCVD process for the deposition of nanotextured boron doped ZnO films used as rough TCO for TF Si solar cells. This paper is a general review and synthesis of the study of the electrical, optical and structural properties of the ZnO:B that has been performed at IMT-EPFL. The influence of the free carrier absorption and the grain size on the electrical and optical properties of LPCVD ZnO:B is discussed. Transport mechanisms at grain boundaries are studied. It is seen that high doping of the ZnO grains facilitates the tunnelling of the electrons through potential barriers that are located at the grain boundaries. Therefore, even if these potential barriers increase after an exposition of the film to a humid atmosphere, the heavily doped LPCVD ZnO:B layers show a remarkable stable conductivity. However, the introduction of diborane in the CVD reaction induces also a degradation of the intra-grain mobility and increases over-proportionally the optical absorption of the ZnO:B films. Hence, the necessity to finely tune the doping level of LPCVD ZnO:B films is highlighted. Finally, the next challenges to push further the optimization of LPCVD ZnO:B films for thin film silicon solar cells are discussed, as well as some remarkable record cell results achieved with LPCVD ZnO:B as front electrode. [Copyright &y& Elsevier]

Abstract: This article reviews the results obtained in Kaiserslautern for research and development on amorphous (a-Si:H) and microcrystalline (μc-Si:H) silicon based thin film solar cells as well as heterojunction solar cells applying entirely or mainly the HWCVD. The activities of the group cover the development of appropriate intrinsic and doped a-Si:H and μc-Si:H films for the different solar cell structures, the realization of many types of such structures with different deposition sequences and the detailed study of their stability behavior. Also the preparation of an HW solar cell on medium size area is demonstrated. Initial and stabilized conversion efficiencies are presented and discussed for the different cell structures realized within about ten years of activity. Main focus will be on the recent activities dealing with the integration of μc-Si:H films into solar cell structures and the extensive study of their stability behavior. In addition the degradation of the applied Ta catalyzer was intensively investigated. Finally advantages and disadvantages will be discussed concerning the commercial use of the HWCVD for solar cell fabrication. [Copyright &y& Elsevier]

Abstract: We present an improved process for free-standing monocrystalline silicon (FMS) thin film solar cells developed at IMEC. We demonstrate that a thick annealed porous layer, or the quasi-monocrystalline silicon (QMS) layer, incorporated into a two-side contacted thin film solar cell structure does not produce any considerable series resistance. The best cell so far exhibits a conversion efficiency of 12.6% with a fill factor of 75.7% for an active layer thickness of 20 μm. This cell process includes emitter formation by phosphorous diffusion, silicon nitride deposition for antireflection coating and front surface passivation, and 50-μm-thick annealed porous layer remained on the rear. Despite the expected small reduction in solar cell''s efficiency, maintaining the porous layer in the device structure renders the processing and handling of the thin FMS film much easier, thus leading to a better yield and up-scalability. PC1D simulations show that a thick QMS layer can lessen the short circuit current density in some degree, depending on the active layer quality, thickness, optical confinement, etc., while the other cell parameters remain substantially unvaried; a 10% to 15% higher process yield is expected to be sufficient to reach a break-even between the two processes. [Copyright &y& Elsevier]

Abstract: During the last two decades, the Institute of Microtechnology (IMT) has contributed in two important fields to future thin-film silicon solar cell processing and design: (1) In 1987, IMT introduced the so-called “very high frequency glow discharge (VHF-GD)” technique, a method that leads to a considerable enhancement in the deposition rate of amorphous and microcrystalline silicon layers. As a direct consequence of reduced plasma impedances at higher plasma excitation frequencies, silane dissociation is enhanced and the maximum energy of ions bombarding the growing surface is reduced. Due to softer ion bombardment on the growing surface, the VHF process also favours the formation of microcrystalline silicon. Based on these beneficial properties of VHF plasmas, for the growth of thin silicon films, plasma excitation frequencies fexc in the range 30–300MHz, i.e. clearly higher than the standard 13.56MHz, are indeed scheduled to play an important role in future production equipment. (2) In 1994, IMT pioneered a novel thin-film solar cell, the microcrystalline silicon solar cell. This new type of thin-film absorber material––a form of crystalline silicon––opens up the way for a new concept, the so-called “micromorph” tandem solar cell concept. This term stands for the combination of a microcrystalline silicon bottom cell and an amorphous silicon top cell. Thanks to the lower band gap and to the stability of microcrystalline silicon solar cells, a better use of the full solar spectrum is possible, leading, thereby, to higher efficiencies than those obtained with solar cells based solely on amorphous silicon. Both the VHF-GD deposition technique and the “micromorph” tandem solar cell concept are considered to be essential for future thin-film PV modules, as they bear the potential for combining high-efficiency devices with low-cost manufacturing processes. [Copyright &y& Elsevier]

Abstract: The drift length Ldrift = μτE within the i layer of a-Si:H solar cells is a crucial parameter for charge collection and efficiency. It is strongly reduced not only by light-induced reduction of μτ, but also by electric field deformation ΔE by charges near the p–i and i–n interfaces. Here, a simple model is presented to estimate contributions of free carriers, charges trapped in band tails and charged dangling bonds to ΔE. It is shown that the model reproduces correctly trends observed experimentally and by ASA simulations: charged dangling bonds contribute most to ΔE of meta-stable cells. Electrons trapped in the conduction band tail near the i–n interface lead to the strongest field deformation in the initial state, while positively charged dangling bonds near the p–i interface get more important with degradation under AM1.5g spectrum. The measurable parameter V coll is proposed as an indirect parameter to estimate the electric field, and an experimental technique is presented that could enable the distinction of defects near the p–i and the i–n interfaces. [Copyright &y& Elsevier]

Abstract: High deposition rate and efficient gas usage are important advantages of Hot Wire Chemical Vapor Deposition (HWCVD). However, the high atomic hydrogen fluxes and high substrate temperature that are involved with the deposition of a-Si and μc-Si i-layers by this technique are generally disadvantageous for the earlier deposited layers and TCOs. To prevent this, we developed doped layers that show high stability against these extreme i-layer deposition conditions. In n-i-p solar cells with an a-Si absorber layer deposited at high rate (16 Å/s) and high substrate temperature (430 °C), best efficiencies were obtained with a μc-Si n-layer deposited by a layer-by-layer process using very high frequency plasma enhanced chemical vapor deposition at high substrate temperature. [Copyright &y& Elsevier]

With the development of the Internet of Things (IoT), indoor photovoltaics are attracting considerable interest owing to their potential to benefit various IoT-related fields. Therefore, this study investigates the use of transparent hydrogenated amorphous silicon (a-Si:H) solar cells for a broad range of applications, including indoor light harvesting. High-gap triple layers were employed in the a-Si:H solar cells to obtain a high shunt resistance and high short-circuit current, J SC , and open-circuit voltage, V OC , under indoor illumination. Additionally, multiple color-adjusting layers were added without noticeable costs to the conversion efficiency. The maximum efficiency of 36.0% was obtained at a transmittance of 20.44% under white LED light (3000 lx and 0.92 mW cm -2 ). Furthermore, the fabricated transparent solar cells show excellent long-term performance, sustaining over 99% of original efficiency under continuous indoor light illumination for 200 h. These cells could accelerate the progress of energy harvesting in IoT applications and facilitate the construction of integrated photovoltaics.

Deposition of amorphous silicon thin films via plasma‐enhanced chemical vapor deposition (PECVD) and batch‐to‐batch operation under run‐to‐run control of the associated chambered reactor are presented in this work using a recently developed multiscale, three‐dimensional in space, computational fluid dynamics model. Macroscopic reactor scale behaviors are linked to the microscopic growth of amorphous silicon thin films using a dynamic boundary which is updated at each time step of the transient in‐batch simulations. This novel workflow is distributed across 64 parallel computation nodes in order to reduce the significant computational demands of batch‐to‐batch operation and to allow for the application and evaluation in both radial and azimuthal directions across the wafer of a benchmark, run‐to‐run based control strategy. Using 10 successive batch deposition cycles, the exponentially weighted moving average algorithm, an industrial standard, is demonstrated to drive all wafer regions to within 1% of the desired thickness set‐point in both radial and azimuthal directions across the wafer surface. This is the first demonstration of run‐to‐run control in reducing azimuthal film nonuniformity. Additionally, thin film uniformity is shown to be improved for poorly optimized PECVD geometries by manipulating the substrate temperature alone, without the need for re‐tooling of the equipment. © 2018 American Institute of Chemical Engineers AIChE J, 65: e16400 2019 [ABSTRACT FROM AUTHOR]