#Risen Energy #Ultra-Thin Wafers #Heterojunction Technology

Introduction

The solar energy industry is at a pivotal moment, grappling with the need for advanced technologies to meet future demands. Risen Energy has been at the forefront of this change, successfully developing and implementing ultra-thin silicon wafers in heterojunction solar cells. This article explores Risen Energy’s journey from concept to large-scale production, highlighting key innovations and technical advancements that are shaping the future of solar technology.

The Background of Ultra-Thin Wafers

The discussion surrounding space photovoltaics has brought to light several critical technical features that solar technologies must possess, such as lightweight construction, high power output, radiation resistance, and long-term reliability. At the core of Risen Energy’s focus is the application of ultra-thin silicon wafers in Heterojunction Technology (HJT).

But why target thin wafers? According to Risen Energy’s research, silicon wafers account for 55% of the cost structure in HJT solar cells, making their reduction the most direct route to cost savings.

Innovations in HJT Technology

The release of Risen Energy's technical white paper outlines the development and industrial application of ultra-thin silicon wafers. Here are key insights:

1. The Necessity of Being Thin

Using thinner wafers goes beyond just cost savings. The low-temperature production process of HJT cells, combined with a fully symmetrical cell structure, reduces risks associated with wafer warping and breakage—common in traditional high-temperature processing methods. Thin wafers are thus not only compatible with HJT technology but also represent a significant inherent advantage.

2. Achieving Reliability

Risen Energy has conducted numerous tests focusing on efficiency, yield, and mechanical strength. They discovered that while short-circuit current decreased with reduced wafer thickness, open-circuit voltage showed an increase. Their HJT Hyperion cells, made with 110-micron wafers, have achieved an average efficiency of 26.4%, showcasing that reducing wafer thickness does not hinder overall performance.

3. Optimized Manufacturing Processes

By redesigning their wafer cassette configurations and optimizing automation transfers, Risen Energy has achieved a consistent yield above 99.5%, with fragmentation rates under 0.25%. Their systematic innovations counter challenges associated with wafer thinning, resulting in enhanced manufacturing efficiency.

4. Examining Mechanical Strength

Tests indicated that conventional 150-micron PERC and 130-micron TOPCon cells broke under bending stress, while cells thinner than 100 microns exhibited impressive flexibility. This flexibility opens doors for lightweight modules and specialized applications, particularly in demanding environments.

5. Addressing Space Applications

Risen Energy's current HJT Hyper-ion products for ground PV applications utilize 110-micron silicon wafers. For space photovoltaics, where performance-to-weight ratio is critical, Risen Energy can produce cells with a thickness of less than 70 microns, thanks to their years of experience.

6. Engineering Innovations

Traditional high-temperature soldering techniques are unsuitable for ultra-thin cells. In response, Risen Energy developed the