AXT INC

To the Board of Directors and Stockholders of AXT, Inc.

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of AXT, Inc. (a Delaware corporation) and its subsidiaries (the “Company”) as of December 31, 2023, and 2022, and the related consolidated statements of operations, comprehensive income (loss), stockholders’ equity, and cash flows for each of the three years in the period ended December 31, 2023, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023, and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the Company’s internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control—Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), and our report dated March 15, 2024, expressed an unqualified opinion thereon.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matters communicated below are matters arising from the current period audit of the consolidated financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.

Inventories – Reserve for Excess and Obsolete Inventory

As described in Notes 1 and 3 to the consolidated financial statements, the Company’s consolidated inventories balance was $86.5 million as of December 31, 2023, which was net of a reserve of $21.9 million for excess and obsolete inventories. The Company’s inventories are stated at the lower of weighted average costs (approximated by standard cost) or net realizable value. The Company routinely evaluates the levels of its inventories in light of current market

conditions in order to identify excess and obsolete inventories, and to provide a reserve for certain inventories to their estimated net realizable value based upon the age, quality and life expectancy of the product, and the projections for sale of the completed products. If actual demand were to be substantially lower than estimated, there could be a significant adverse impact on the carrying value of inventories and consolidated results of operations.

The principal considerations for our determination that performing procedures relating to reserve for excess and obsolete inventories is a critical audit matter are the significant amount of judgment by management in developing the assumptions of the forecasted product demand, which in turn led to significant auditor judgment, subjectivity, and effort in performing audit procedures and evaluating audit evidence relating to the forecasted product demand. Additionally, for certain new product launches there may be limited historical data with which to evaluate forecasts.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of internal controls relating to management’s reserve for excess and obsolete inventories, including internal controls over the development of assumptions related to forecasted product demand. The procedures also included, among others, testing management’s process for developing the reserve for excess and obsolete inventories, testing the completeness and accuracy of the underlying data used in the estimate, and evaluating management’s assumptions of forecasted product demand. Evaluating management’s demand forecast for reasonableness involved considering historical sales or usage by product, comparing prior period estimates to actual results of the same period, and determining whether the demand forecast used was consistent with evidence obtained in other areas of the audit.

/s/BPM LLP

We have served as the Company’s auditor since 2004.

San Jose, California

March 15, 2024