Crystalline silicon solar cells have attracted great attention for their various advantages, such as the availability of raw materials, high-efficiency potential, and well-established processing sequence. Tunnel oxide passivated contact (TOPCon) solar cells are widely regarded as one of the most prospective candidates for the next generation of high-performance solar cells because an efficiency of 26% has been achieved in small-area solar cells. Compared to n-type TOPCon solar cells, the photo conversion efficiency (PCE) of p-type TOPCon is slightly higher. The highest PCEs of p-type TOPCon and n-type TOPCon solar cells are 26.0% and 25.8%, respectively. Despite the highest efficiency in small-area cells, limited progress has been achieved in p-type TOPCon solar cells for large are due to their lower carrier lifetime and inferior surface passivation with the boron-doped c-Si wafer. Nevertheless, it is of great importance to promoting the p-type TOPCon technology due to its lower price and well-established manufacturing procedures with slight modifications in the PERC solar cells production lines. The progress in different approaches to increase the efficiencies of p-type TOPCon solar cells has been reported in this review article and is expected to set valuable strategies to promote the passivation technology of p-type TOPCon, which could further increase the efficiency of TOPCon solar cells.

Thin film transistors (TFTs) with large-area, high mobility, and high reliability are important factors for next-generation displays. In particular, thin transistors based on IGZO oxide semiconductors are being actively researched for this application. In this study, several methods for improving the reliability of a-IGZO TFTs by applying various materials on a passivation layer are investigated. In the literature, inorganic SiO₂, TiO₂, Al₂O₃, ZTSO, and organic CYTOP have been used for passivation. In the case of Al₂O₃, excellent stability is exhibited compared to the non-passivation TFT under the conditions of negative bias illumination stress (NBIS) for 3 wavelengths (R, G, B). When CYTOP passivation, SiO₂ passivation, and non-passivation devices were compared under the same positive bias temperature stress (PBTS), the Vth shifts were 2.8 V, 3.3 V, and 4.5 V, respectively. The Vth shifts of TiO₂ passivation and non-passivation devices under the same NBTS were -2.2 V and -3.8 V, respectively. It is expected that the presented results will form the basis for further research to improve the reliability of a-IGZO TFT.

In order to achieve a high efficiency for the silicon solar cell, a passivation characteristic that minimizes the electrical loss at a silicon interface is required. In this paper, we evaluated the applicability of the oxide film formed by ozone for the tunnel silicon oxide film. To this end, we fabricated the silicon oxide film by changing the condition of ozone oxidation and compared the characteristics with the oxide film formed by the existing nitric acid solution. The ozone oxidation was formed in the temperature range of 300~500℃ at an ozone concentration of 17.5 wt%, and the passivation characteristics were compared. Compared to the silicon oxide film formed by nitric acid oxidation, implied open circuit voltage (iVoc) was improved by ~20 mV in the ozone oxidation and the ozone oxidation after the nitric acid pretreatment was improved by ~30 mV.

We investigated solution-processed indium-yttrium-oxide (IYO) TFTs using apoly (methyl methacrylate) (PMMA) passivation layer. The IYO semiconductor solution was prepared with 0.1 M indium nitrate hydrate and 0.1 M yttrium acetate dehydrate as precursor solutions. The solution-processed IYO TFTs showed good performance: field-effect mobility of 13.13 ㎠/Vs, a threshold voltage of 8.2 V, a subthreshold slope of 0.93 V/dec, and a current on-to-off ratio of 7.2 × 10⁶. Moreover, the PMMA passivation layers used to protectthe IYO active layer of the TFTs, did so without deteriorating their performance under ambient conditions; their operational stability and electrical properties also improved by decreasing leakage current.

Minimizing the carrier recombination and electrical loss through surface passivation is required for high efficiency c-Si solar cell. Usually, SiN_{X}, SiO_{X}, SiON_{X} and AlO_{X} layers are used as passivation layer in solar cell application. Silicon oxide layer is one of the good passivation layer in Si based solar cell application. It has good selective carrier, low interface state density, good thermal stability and tunneling effect. Recently tunneling based passivation layer is used for high efficiency Si solar cell such as HIT, TOPCon and TRIEX structure. In this paper, we focused on silicon oxide grown by various the method (thermal, wet-chemical, plasma) and passivation effect in c-Si solar cell.

With the recent advent of through silicon via (TSV) technology, wafer level-TSV interconnection become feasible in high volume manufacturing. To increase the manufacturing productivity, it is required to develop equipment for backside passivation layer deposition for TSV wafer bonding process with high deposition rate and low film stress. In this research, we investigated the relationship between process parameters and the induced wafer stress of PECVD silicon nitride film on 300mm wafers employing statistical and artificial intelligence modeling. We found that the film stress increases with increased RF power, but the pressure has inversely proportional to the stress. It is also observed that no significant stress change is observed when the gas flow rate is low.

Aluminum oxide(Al2O3) film deposited by atomic layer deposition (ALD) is known to supply excellent surface passivation properties on crystalline Si surfaces. Since Al2O3 has fixed negative charge, it forms effective surface passivation by field effect passivation on the rear side in p-type silicon solar cell. However, Al2O3 layer formed by ALD process needs very long process time, which is not applicable in mass production of silicon solar cells. In this paper, plasma-assisted ALD(PA-ALD) was applied to form Al2O3 to reduce the process time. Al2O3 synthesized by ALD on c-Si (100) wafers contains a very thin interfacial SiO2 layer, which was confirmed by FTIR and TEM. To improve passivation quality of Al2O3layer, the deposition temperature was changed in range of 150∼350℃, then the annealing temperature and time were varied. As a result, the silicon wafer with aluminum oxide film formed in 250℃, 400℃ and 10min for the deposition temperature, the annealing temperature and time, respectively, showed the best lifetime of 1.6ms. We also observed blistering with nanometer size during firing of Al2O3 deposited on p-type silicon.

Citations

• Properties of liquid phase deposited aluminium oxide thin film on black silicon fabricated by aluminium-assisted chemical etching
  Suleman Kazim Omotayo, Nuranis Liyana Muhamad Burhan, Mohd Marzaini Mohd Rashid, Mohd Zamir Pakhuruddin
  Physica Scripta.2025; 100(3): 035545.     CrossRef

Surface passivation of AlGaN/GaN heterojunction structure was examined through the thermal oxidation of evaporated Al. The Al-oxide passivation increased channel conductance of two dimensional electron gas (2DEG) on the AlGaN/GaN interface. The sheet resistance of 463 ohm/□ for 2DEG channel before Al2O3 passivation was decreased to 417 ohm/□ after passivation. The oxidation of Al induces tensile stress to the AlGaN/GaN structure and the stress seemed to enhance the sheet carrier density of the 2DEG channel. In addition, the Al2O3 films formed by thermal oxidation of Al suppressed thermal deterioration by the high temperature annealing.

We have analyzed electrical characteristics of spot light solar cell modules and have completed fabrication of spot light solar cell modules. Before we test modules, we have carried about UV test of hologram. As a result of test, we have obtained 165% efficiency of hologram film. the other hand, we obtained 75% efficiency of general films. After we have fabricated solar modules and carried about field test, spot light solar cell modules with hologram have been investigated 17.3 A of Isc and 155.4 W of power.

This paper was carried about thermal analysis for high efficiency point contact solar cell. Therefore, we carried about 2-D device and process simulator according to design and process parameters. As a result of simulations, power transfer efficiency have decreased more increasing temperature. Especially, power transfer efficiency of room temperature have been showed 25%. The other hand, power transfer efficiency of 350 K kalvin temperature have been showed 20%. Therefore, we will considered design with thermal dissipation of device.

This paper was carried about optimization for high efficiency of point contact solar cell. We have studied on the characteristics of power converter according to each parameter for the optimization for high efficiency of point contact solar cell on this study. We have 25.1352% of convert efficiency after adapt optimal parameters as mentioned in point body and superior conclusion is drawn by comparison with general efficiency has within 20%. At this time, the value of parameter is 100 um cell pitch, 0.01 um AR coating, 0.9 um N+ FSF thickness., etc. This study will continue to go on for optimization for efficiency in future, as it looks now, the results of this study would contribute to the business of high efficiency of point contact solar cell.

Citations

• Effect of Pre/Post-Treatment on the Performance of Cu(In,Ga)(S,Se)2 Absorber Layer Manufactured in a Two-Step Process
  A-Hyun Kim, GyeongA Lee, Chan-Wook Jeon
  New & Renewable Energy.2021; 17(4): 36.     CrossRef

Citations

• Effects of Organic Passivation Films on Properties of Polymer Solar Cells with P3HT:PC61BM Active Layers
  Sang Hee Lee, Byung Min Park, Yang Keun Cho, Ho Jung Chang, Jae Jin Jung, Jaeho Pyee
  Journal of the Microelectronics and Packaging Society.2014; 21(4): 105.     CrossRef